Well,
i pivoted the plan to utilizing a bus.
i picked up a 2004 Eldorado Aerotech shuttle bus based off a E450 chassis this weekend.
Like the campers I was looking at, it is a 1 piece fiberglass shell except the cab itself, so I have something that should be relatively water tight once i reseal the windows. I think i'm going to boat tail it, but, instead of having some kind of external storage only in the boat tail, i'm going to build out a walk around queen bed on a raised platform inside the tail - assuming the clearances work out.
I'm torn - on one hand, i think it'd be really cool to get a 3d scan of the bus and maybe do some fluid dynamics modeling, on the other it'd be easier to do the "tuft test" but doesn't look as cool..