Not to throw a damper on the swivel seat topic, and I do think it's a great idea, but are there any regulations prohibiting that kind of application?
I also need to weigh in on the Rialta. It has a slide out, temporary bathroom, and I question the robustness of the VW van drivetrain dealing with that weight.
Wantabe: the LTV Serenity is a nice floorplan but I agree about the price. One other thing, think REAL carefully about whether you want to do without a dry bath. For us, especially after having one, it would be non-negotiable.