Rialtas are hard to find parts for, if not impossible, and if you do find them they are very expensive. If you don't have time to spend hunting down parts, and doing repairs yourself, expect to pay a mechanic a lot of money. Why bother with the hassle when there are so many good Roadtreks in your price range. As far as size, you will do fine in a Class B, don't listen to the nay sayers. What you give up in size, will be more than made up for by the maneuverability, and places you can go, and camp.
I guess I'm one of those Rialta bashers, but for good reason. :E