Here is the link to my interior thread.
viewtopic.php?f=10&t=6098
I have a murphy bed design in mind for something, somewhere, sometime, someday.
Its only in sketch form... I don't know if I saved it, but I could draw it up again if you have any interest.
It has the potential for the bed to fold up, dinette fold down from it, and a bench on the opposite side to connect to. With storage.
I am weak in the water/electric design/build area, so those would be other components to design in.
A van is certainly a jigsaw puzzle to make use of space efficiently. I always plug Van Specialties of Portland Or - they can bring your idea to life if its worth building. They made my idea reality.
Good luck, take your time, and brainstorm!