I would buy a 3500 Chevy Van with the 6L and take it to a conversion shop (Sportsmobile?) and have them add the top of my choice to get some height. Then I would have a proven, trouble free vehicle with plenty of power to pull anything I want to pull, tall enough to stand up in, I could park anywhere and virtually any mechanic anywhere in the country could do most things to it. I could convert that baby to my specs and needs and have a ball doing it.
I did what you are doing back many years ago and we enjoyed the heck out of the van for two decades. After we quit using it to camp, we used it for a "hauler" and they can carry as much as most half ton pickups and everything is enclosed. I still miss that old van. I have owned Fords, Dodges and Chevy vans. I will never own a Sprinter because of the service problems if you happen to be outside a metro area.
To each his own. That is why all those brands are out there.
Paul
