First off, thank you to all the contributors.
I'm interested in building a camper as most of our camping is done in the Rockies and my wife and kids invariably get too cold to sleep in a tent. I don't really like pop ups, they always seem to end up smelling bad and still tend to get fairly cold. The only TV we have is a 2000 Toyota Sienna (3500 lbs tow rating).
I'd love to make a foamie that can sleep 4, fits in the slipstream of the van, has a GVWR under 2800 lbs, and has an outdoor kitchen. I've done some searches and can't really find a vehicle that fits those criteria. It wouldn't have to be large, but I'd like it to be able to fit four sleeping adults. So maybe 12 ft long with some sort of multi-tier sleeping arrangement where the bunks overlap. I don't care about pretty, but I would like something that was functional and affordable.
I'm not opposed to designing something on my own, but I find it's always advantageous to stand on the shoulders of giants.