Searching for right RV for cross country with disabled son.

To me it sound like you should look at a van conversion or class B motorhome. I realize you had a conversion van, but there are many many configurations, including seating for 6, a small kitchenette and small bathroom. There many different plans out there, take a look at sportsmobile.com, to get an idea of the possibilities. There are many options available used in the price range you are looking at.