I own a 2002 Honda Odyssey and it's a great car, but the transmissions are notorious for failing. I had the transmission replaced at 24,000 miles as part of recall and I know others' odysseys that have failing transmissions too. Otherwise, the car has been mostly problem free except for a steering rack replacement, startor, and alternator. And many timing belts.
I'd recommend the 2003 Honda Element. The higher price of the Element will make up for repair bills of most other cars you'll look at. The Element literally sounds like the perfect car for you. It's made for the active person in mind with a clamshell tailgate and wide opening side cargo doors. The car is almost as simple as it gets. It's offered in a manual in 4WD and 2WD versions.
This car is made for sleeping in. The seats fold down open and flat. They were offered with a removable skylight when they were new. The carpet and seat fabric are stain resistant and can be cleaned by wiping them. I almost bought one of these in 2005, but bought a Prius instead because of HOV lane stickers and fuel economy. I definitely think this is the car for you.