With that TV and your family size, your best bet is still a popup. If headroom is tight, I think the highwall popups have more interior ceiling height too.
We sleep our three kids on ONE of the king size bed ends longitudinally. Plenty of room, but they are all girls so that helps. No reason mom, dad and a baby can't use the other king bed. That leaves one kid on the couch and one on the dinette. Dinette wrestling is a hassle, but if your oldest is a boy, just kick him out into a pup tent when he turns 9. Worked great for me when I was a boy!
