I'm a very large guy, and beds and toilets are gonna have to fit me.
Many makers of campers buy prefab bathroom units. I've encountered 1 design in particular in 3 different brands owned by family members and friends. It's horrible. The toilet sits facing the center line of the camper. To get the drain inside the trailer frame, they moved the toilet forward 6" and it's too close to the wall. You can barely stand up because you can't lean forward to get your balance. You even have to work at keeping your balance to stand in front of it to pee.
Most RV bathrooms aren't made for big people but there are some out there that are. Find one that fits even if you don't like the camper. Then start researching floor plans and look for that particular bathroom unit.
