Has anyone purchased a Rialta from Poptop Heaven..

Not to pick nits, but the Rialta is a class C, not a B. I had a 1998 Rialta with the twin bed option (FD version). I’m not sure what you mean by foldable bathroom, but the Rialta bathroom slides out and to me was a real PIA. But you may have different opinion. No clue on your dealer. I would ask who in the area will work on it. None of the three VW dealers in my area (at the time) would touch it. I had to take it to a independent shop and they did good work.