I’m wondering if you might be underestimating the pain the in ass a massive tent like that could be to set up. The first one you posted a while back looks closer to the big old canvas tents we used to set up in the USMC that took 5 of us an hour to set up, granted your kids are probably smarter than any 5 average jarheads. A basic 4 person tent with flexible poles will go up in 2 minutes by a single person. Of the above, I like the simplest one, the 10x14.
But I get that you have pressure from the family with certain expectations on the tent. Just make sure you factor in how much fun they’ll be having helping set set up and tear down that thing. I think a big complex tent would quickly make my kids associate camping with more chores. My perspective might also be different because we often camp one night at a time for a quick getaway or a different spot each night on road trips. If I were going to be in one spot 3 or 4 days at a time I might value a bigger tent more.
Also, guy lines are a red flag… there are so many campsites without room or suitable ground for staking in guy lines, another advantage of a freestanding tent.
On mattresses, when we car camp we sleep on Exped MegaMats. It’s the most comfortable camping mattress I’ve ever been on. Combination of foam and air. Thermorest MondoKing, Nemo Roamer, and Exped Deepsleep are all similar.