Have you considered a Class A at all? With the amount of $$$ you will be investing (?) you can get a Class A with a King and bunks for the same amount of $ that a 40' 5th and a 3500 Truck. I think Forest River Georgetown and Tiffin make such a floor plan.
But, if you are set on your current set up, I will suggest a RV driving/towing school. Our first RV was a 27'Airstream towed with a Surburban...it was overwhelming at first but we have a close friend that is a retired truck driver and a neighbor that tows a huge boat...both of them took us out for extended lessons at an empty Post Office lot on Sundays. Both my hubby and I could put that Airstream exactly where we wanted it, most on the first try. But it took alot of practice! By the time we ventured on our first trip, we were confident in our driving/handling/backing of the trailer...which took alot of stress off our trips. Enjoy your search and safe travels to your family.
