It sounds like you are not thinking of a tiny house in the sense that most of us would think of one, but of doing a bus conversion, which is still an RV in the traditional sense. You would still end up buying many of the same components that we all have trouble with and if you get an used shuttle bus, still have a used vehicle that will have problems. So I doubt you will be any more trouble free that most RVers, but you will have something you built and you will love. So go for it. I think it is a great idea.