BeaumontV

hello folks, I am new here and just putting together the plan for my wife and I to escape and travel around the Rockies. I want to buy an NV 3500 (preferably 4x4) and use it for overnight camping sometimes, and sometimes use it to tow an Airstream. Are there any modular kits for converting the cargo van into a camper out there? I can find them for the Sprinter and ram, but those things aren't strong enough for my needs. Thanks. Beaumont