The shower sounds like a awesome idea. If I wasn't using it for a MC lift, I would do that.
I came from teardrop trailers, and I hate class a's. I think they're crap. And I would love a lift that way I can boodock at track days and traveling period. Maybe every now and then stop at a campground. But I'm a stop at a rest area/keep moving kind of guy.
My dream rig ( this one is for sale for $8k):
Old setup I built from scratch. Even the frame: