Always size up on tent. If there's 4 of you, get at least a 5 man. Even outwell admit in their website that 4 man tents are not really meant for 4 people living in, they merely have enough room for 4 to lie down.
Inflatable tent - makes the putting up and taking down infinitely easier. It's what we're upgrading to shortly after tent envy in our last few holidays.
Tent with enough area to sit inside with a table for games etc when weather is poor. And a covered porch area for taking shoes off etc.
Black out sleeping areas.
Electric hook up plus plug in cool box and kettle (and toaster if that's what you like of a morning). If you get really chilly you might even want to consider a small fan heater.
Good lighting. Lots of the LEDs are bright white and harsh. Look for warm white. You even get some that you can change the tone.
Decent camp cupboard/kitchen to store all your plates, cups etc.
Deep inflatable mattresses and good sleeping bags (or duvets plus pillows and sheets). I always put a sheet on even if using sleeping bags. Keeps chill and condensation at bay.
Don't underestimate the space it all takes to pack in your car. We have a massive estate car but still need a roofbox. We're looking to upgrade to a covered trailer.