The “berth” of a tent is based on very narrow dimensions.
We are a family of 4 (dcs are 6&8) and we have a five man tent which is getting on the small side now.
We need to move up to a 6-8 man tent for the bedrooms to be big enough.
Personally I’d go with poles if it’s always two of you putting a tent up, rather than an air tent - only because I know of a couple of people with air tents who’ve had punctures etc (but they are getting better), whereas poles are easily replaced.
Make sure you have decent sleeping arrangements. We’ve gone for traditional rubberised cotton air beds which can be inflated to your comfort. For the dcs they had toddler air beds with raised sides to keep them contained.
We take duvets and proper pillows now instead of sleeping bags. Plus hot water bottles and layers to go underneath you between you and the air bed.
If you camp when it’s cool at night, you need extra layers. So I have proper real wool army style blankets. These are also safe for sitting around the fire at night as they’d not flammable.
Cooking - get a decent gas stove and a couple of pots/pans.
Tables and chairs - we have three tables (!) and four chairs. Two tables are for cooking/storing and the third is for eating at. An absolute god send.
I also have two large picnic blankets. One for outside the tent at all times and the other is carpet inside the tent. It’s handy for when we pack up - as everything can sit on the blanket. Also it is useful for when it’s raining - shoes off outside the tent on the picnic blanket.
Lighting - torches and fairy lights. Fairy lights are super useful for lighting up the tent so you can find it on the way back from late toilet trips!!!
Pick a site with decent facilities. It’s not the time to be roughing it when you’ve got kids. Also somewhere with space for games.