Just a thought or maybe a couple thoughts :)
It's interesting how so many respondents are still showing you units over your specified length. People naturally want to show off their units and defend their expenditures.
Another thing though you need to consider .. most of these unit that have nice theater seating directly across from the TV have apposing slides. You also stated you like to camp in National Parks and the like. My humble experience has taught me that not only are lots of those camping areas more limited in length bu they can also be very difficult with width!
I totally agree with your wants though. I can't believe some of these rigs that you either have to sit sideways or look through the kitchen to see the TV. We settled on a unit that, by removing the couch (which we never use) and moving one of the recliners to that side of the room, came about as close as we could get for the overall length and width trailer we wanted.
Just something else to consider.
I have seen a bunch of newer 5th wheels that, if I wanted to go a few feet longer and wider, I would jump at though. I have googled every unit suggested here and there are some awesome rigs out there these days.