For Kent, depends on your budget. Will one of you need to commute into London at all? If so somewhere like Cranbrook would be more of a schlep in.
I’m outer Sevenoaks. Sevenoaks & Tonbridge Wells are considered ‘posher’ than Tonbridge but Tonbridge has hands down the best grammar options (although a lot of our kids all commute to schools between the towns).
Sevenoaks itself is very expensive. It’s a pretty town. It’s not got a great deal of shops (a few high end branches of stores such as Whistles) but there are a lot of restaurants. It’s the shortest commute into London, hence the price tag. We do have our own grammars - as mentioned, the girls Weald Annex and the recently opened Tunbridge Wells for Boys annex, both on the outskirts of town near Seal. But as others have raised, if your DC don’t pass the 11+then your options aren’t great. Knole, the local Secondary hasn’t a great rep (though it does have a grammar stream for DC who narrowly miss the 11+). Trinity, a Faith school is good.. but very oversubscribed and hard to get into on a non Faith place unless you live close. If you don’t fancy Sevenoaks itself, look at Otford (v pretty - has its own train line into London), Shoreham (ditto .. but a slower line I think), Borough Green (not so pretty but ok, own trainline and a decent Secondary - Wrotham), Wrotham and Platt (trains from Borough Green). Otford and Shoreham would be the most expensive, Borough Green the cheapest. We live in Borough Green - from here we are in catchment for the grammars in Tonbridge, Sevenoaks and Maidstone).
Tonbridge is a bit more mixed in terms of demographic but has some very nice properties. Retail wise, it’s all a bit Bonmarche but there are some nice restaurants. Property wise it’s cheaper than either Sevenoaks or Tunbridge Wells and has very frequent trains into London. It has a boys and girls Super selective (Judd and Tonbridge Girls Grammar) and a selective (Weald). If your DC don’t pass the 11*, Hillview girls school is decent but you’d struggle to find somewhere of equal calibre for boys.
Tunbridge Wells is a really nice old spa town and probably my favourite. Grammar wise it’s got a super selective for boys (Skinners), as well as a girls selective (Tunbridge Wells grammar for girls) and a selective boys (Tunbridge Wells grammar for boys).The local state —Skinners Academy - used to have a bad reputation but apparently has come on a great deal and it takes both boys and girls. It has the most restaurants and shops (although like most towns there have been a lot of closures). It’s the longest commute into London.
Medway I don’t know at all. I like the town centre of Rochester - the outskirts a lot less so. It has a very mixed demographic.
I’d also look at West Malling (but not the Kings Hill area) which is very historic and pretty ;DC either can go to grammars in Tonbridge or Maidstone). Some of the villages surrounding Maidstone are very pretty. Maidstone has 4 grammars which are high performing and less subscribed than the Tonbridge etc ones. You’ll also get a lot more house for your money! Maidstone has a direct train line to London.
But honestly, 75% of DC don’t pass the Kent Test in Year 6 so choose where you live really really carefully! Tutoring down here is rife to pass it, often starting in Year 4. Bus services between the towns and the train services too are good so many of our children go to schools in neighbouring towns. As above, as an example from Borough Green, DC go to grammars in Sevenoaks, Tonbridge, Maidstone and Tunbridge Wells and this is pretty common. It does make for long days though for them (my DD who goes into Tonbridge doesn’t get back till 5pm, add in then an hour of homework).
I’d really suggest coming down and spending time here to see what will work for you! Please feel free to message me.