Mike,
I like the idea. However I think that would make it to high for my corolla to comfortably tow. Also, the sleeping area is wide enough to put a double bed between the arches.
I'm also wondering about a couple of thinner storage areas under the floor, near the axle. Just in case I need extra storage after a while.
57plymouth
I do like your idea. As I don't like the visual impact shown in the photos. It's UGLY. Curves plainly more work, but as mentioned earlier, they could be finished later. Although I'd create their floor at the same time as the interior, to reduce the potential for leaks etc.