To each his own, but I have a truck camper and a Jeep, and for any sort of real "offroad" work, I'm in the Jeep. With cabinets full of stuff, and 9000lbs of truck/camper, it just isn't fun running really rough trails with the truck. I think it would be fine for trips to baja, or exploring the desert in Utah, but if the trail gets crawley at all, I'm no longer interested in taking the truck down it for "fun". I'll suffer through it to get to a good campsite, but that's about it. If you think you really want to do serious stuff in your camper rig, then a van or suburban seems like a good way to go, but then you're pretty much stuck to running wide open trials. As soon as they get tight and technical, it becomes un-fun again.
If you're watching for vans, Quigly converted quite a number of Chevy/GMC vans to 4wd using the front end parts from a 2500 chevy truck. I've spent some time under the front and it's very well done. But they're IFS, which limits the offroad ability compared to solid axle. On the plus side, they drive very nice, like a stock van. There are lots of Ford vans out there with solid front axles. They have two advantages over the GM van, one is the solid axle working better when the going gets really rough, and two is the wheelbase being shorter. (Ford runs a longer rear overhang than GM on the longest van.) If you like having a "real frame", then that's a 3rd advantage, but the Unibody construction of the GM van is plenty strong. I've not heard of any issues with it, and it does keep the weight down.
Put some thought into what you really want to do with it, and the make the best choice you can and see what you learn!! I think sometimes there is a lot of fun in learning things for yourself vs. doing what worked best for others...