It is hard to really make any suggestions based on the information provided. If you need to use you TV to transport your "aging parents" around then a F350 or almost any 1-ton pickup may not work. My mother is 5' tall and 86 years old, she can't hop up in my F350.
But you may be 35 years old and your "aging parents" may only be 55 and able to jump right in!
As someone suggested already, start going to RV shows. We did that plus we started going through dealer's lots to get an idea of what we would want. It is a good idea to wait and buy the TV after you buy the TT or fiver. We had just purchased an F350 diesel for our business so we actually did it backwards but it couldn't be helped.