How hot do you want it to be?

August in Italy is very very very hot. Like nasty hot. Enthusiasm for sightseeing plummets and siesta is there for a reason.

I'd also say that Florence is famously boring for kids. There's art, churches and statues and not a lot else.

May is a much nicer time of year.

Lake Garda is heaving in August as are most of the other key resorts and cities. Lake Como is quieter but less child friendly. How about a mountain resort, from where you can day trip to Venice or Milan. Or Tuscany around Pisa or Lucca.

Do a city plus a beach/rural chill

Either Rome and Sorrento

Or Florence and Tuscany

Or the lakes and Venice/Verona

Or Sicily

Don't try to combine too many or you'll just waste your time on trains etc

Another thought from our disastrous road trip experience - just because it looks straight on the map, doesn't mean there isn't a giant mountain in the way.

If all the roads are going up and down and not left to right, there's a reason for it. Also driving in Italy is generally to be avoided.

Viareggio is a good seaside base which you could then take a day trip to Pisa/Florence/Lucca from

Look out for agriturismo, some have restaurants and local produce supermarkets

I agree about the heat but we have done Italy holidays by sticking sightseeing on the end once we had acclimatised a bit so Tuscany and on to Florence and Siena, Umbria and Rome,Neapolitan / Amalfi coast and Naples , Herculaneum, Capri etc.
Bearing in mind the ages of your DC Rome has a lot to offer and you could stay at the coast or in the hills for the bulk of your holiday.An excellent option is Sicily which although hot has an island climate and so much of interest to see and do.

Will you be hiring a car OP? If you are make sure you're a really confident and competent driver. I've just driven the Amalfi coast last week and it was hairy to say the least 😂

I would definitely go in May rather than august. We flew to Rome and spent 4 days there. We then hired a car and drove down to the Amalfi coast. The beaches are lovely and there's Pompeii etc to visit.

There's abroad and there is Italy! The Amalfi coast roads are "interesting" especially with the scantily clad teens on scooters weaving in and out with no apparent regard for other traffic. Sicily saw us going down roads where I got out the car to guide DH and make sure the couple of inches spare road width were evenly distributed both sides of the small car (best not put too much faith in Satnav there). To put in context we are quite happy driving in rural Africa but would think twice about the Amalfi coast or Rome again. Luckily public transport there is very good.

Lol at the driving concerns. I drive in Italy, albeit in the north, and I find the driving a lot worse in France. That said I would avoid driving anywhere in Campania (Naples, Sorrento etc.) as it really is survival of the fittest there. Everywhere else is fine although road quality can vary in the more remote areas and mountain areas quite often have lots of scary hairpin bends that I hate and avoid. The motorways are better than the U.K. although pricey.

alternatively get the train, the high speed trains are cheap and efficient. I would avoid August as not only is it very hot (or else the excessive heat in weeks prior has brought on storms), everything costs about 10x as much. May is usually nice temp wise, although this year we did have a heatwave with temperatures a lot higher than normal.

if you don’t like heat go for the mountains, either Alps or Dolomites. Or else the lakes nearby (Garda, Como, Maggiore, Orta). From there it is usually easy to pop to a town for the day for a bit of culture.

Driving is fine - don't let people put you off. If your DH is a confident driver he will be fine. I'd just avoid driving some of the major areas like into/out of Rome on your very first day. However saying that plenty of people do it and it's absolutely fine, you can just add it to your tick sheet!
We are here at the moment (Puglia) and have roadtripped all over Italy. Driving in/around Rome was definitely the worst we have had. I'd avoid going for too long days driving because you do have to have your wits about you, but most of the motorways are absolutely fine. Although Milan-Bologna is just traffic jam central every time we've done it and we try to avoid that section now unless we absolutely have to.
If you don't drive you will be so much more limited about what you can visit and see especially if you want to get off the main tourist routes.
I love Rome in August, it's my favourite time to go because it's quiet - everyone ships out to the coast and the city becomes really manageable. But it is hot, I can't deny that. May is much cooler (but still sunny and warm usually) but as a result it is heaving.
Beaches on the east coast (Rimini, Pescara, Ancona) will be packed from late July/August with Italian holiday makers and the roads too. Sorrento is busy from may-late September.

If you're doing a week in May, I'd stick to Rome and maybe one/two day trips. There is so much to do there you can easily fill a week especially if you spend some of your days/mornings doing parks etc with the kids. You can get away without a car. The trains are relatively easy.
If you're doing 2 weeks in Summer, id suggest doing it in two parts, or if your kids are comfortable travelling perhaps 3. For example-
Fly into Rome Wednesday. Stay central until Saturday morning. Two full days there.
Saturday get the train to wherever you chose. Pick up a hire car in the local town and drive to villa/agriturismo and stay there sat-sat. Choose somewhere suitable for a day base but easy reach of some good day trips to the beach or fun sites. Then leave Saturday, drop off your hire car and get the train to an alternative city location and spend Saturday - Tuesday/Wednesday there before flying home. You have to be organised about where you've left your car etc in the UK but if you can get it to work flying back from a different location gives you far more options when you are travelling.
Personally I'd fly into Rome, travel up to near Siena and stay in a rural property there. Do day trips to Pisa if you fancy it, otherwise just visit local towns and relax by the pool. Then go to Florence and fly home from there. Alternatively go a bit further and get the train to Turin.
If you only want to do two stops - fly into Rome then stay near Pompeii and do Pompeii/Herculaneum and some of the coast etc before travelling back via Rome. You don't have to stay except perhaps for one night to make flight times easier.

We've driven in many areas of Italy, fine as long as you avoid city centres and Lake Garda was horrendously congested along the east lake road. Parking can be a nightmare though.

Thing is you may always have wanted to visit Florence but why and have your children?

There is a reason that Florence always turns up on the 'most disappointing holiday' threads. People think it's an amazing destination (which it is) but it's small, and if you aren't into mainly religious art, you are prob going to think WTF. While Rome has something for everyone.

We did Florence this year and it was the holiday of a lifetime but we didn't see anyone there with children.

If you go to Rome then Florence is only an hour away on the high speed train. Easy for a day trip. Rome is the bees knees and there is an amazing light show in the Fori Imperiali I took my DD to when she was about 8. Also you can get a train down to the beach as Rome is near the coast, although apparently the nicer beaches are further afield (disclaimer, I’ve never been to Ostia or anywhere coastal and Roman).

I went to Italy in August and it was so hot we just wanted to stay in the cool pool, so May would definitely be a better choice. For me, I loved Venice and Rome, and Sorrento and Capri for a more relaxed vibe. Florence was boring as hell, I'll be honest, I really can't imagine kids enjoying it.

If you go to Florence for the day you can get it done and dusted and it won’t be boring for the DC. No need to go to the Uffizi, just a wander round the piazze and the markets, plus a few minutes on the Ponte Vecchio, ice cream, aperitivo then back on the train to Rome. Maybe watch the Medici series beforehand to make it more interesting. It used to be on Prime but that was ages ago, no doubt it will be available somewhere.

For the beach part there are quite a few within easy reach of Rome and on a train route. I will ask my Roman friends where they recommend. Most seem to have beach houses in Southern Tuscany though (Argentario), not sure what to read into that! At the worse you can pop over the Appenines to the Adriatic coast.

Venice will be an absolute nightmare in August.

Rome I'd recommend side trips to Ostia Antica and the Villa d'Este in Tivoli which is a lot of fun.

The area around Bolzano is lovely with plenty to do.