We have a 40' RV. Two Labs and a Newfie required it! lol I have seen some of the vehicles you mentioned and they are really nicely equipped. There is a woman traveling solo parked across from us and she has a nice small self contained unit and is really happy with it. We are heading east the end of the month. Came across country this past October.
RE: Things to consider with buying a van to convert into a camper