I'm working through this in my design as well.
Thinking of doing a bit more angled trailer, more offroad style and less curves on the front and back. This would allow me to possibly install brackets at both ends and run a cot/hammock parallel to the bed above it. That would make it removable when not in use but we can still fit our 5'7" and growing daughter and two boxers in a camper on the 5x8 frame I'm buying. Thanks for posting this as I love to read the ideas and see if there is a better design to use!
Ryan