Diy Camper Opinions

Your choice of trucks is solid though. OBS or early Super duties, or 2nd Gen Rams. First gen lack some heavy duty to them and GM doesn't have a real viable option in that era.

Could be an awesome project, but you'll need some serious tools and some real fab/construction skills to not make a rolling gypsy mobile that looks like something out of a movie.
Check out a couple threads on here for some ideas. A guy up here made a 2 pod camper on a flatbed. Super sweet ingenious setup, but the time money and skill that went into it was considerable to say the least.
I'd save the construction projects for making money and buy a camper to slap on a truck and get to living the life! Unless you could do something like graft a small class C camper onto a F550 or some big dually.

The big issue will be weight, the provan you're looking at is super light. Like a pop up TC or less. To make a sturdy, full feature, well constructed camper will be pretty heavy I think and without engineering ability for wood or at least common sense fab skills with aluminum or steel frames, it will be tough to build something "bulletproof."
That said, still sounds like fun. Weigh the practicality though.

If you plan to travel across the country and be in the south during the summer or in the midwest or north during the winter, insulation is your friend. You probably can't put too much in there.

Not a bad idea Bedlam and I bet there will be a ton (literally) available with all the hurricane wrecked ones in Florida and Texas.

I suggest you buy a late model trailer that has been wrecked for all of the appliances and some of the windows. Trying to buy these new or piecemeal will quickly get expensive. If the frame and axle are still worth saving, you can convert the trailer to a flatbed for your own use or resell it to recover some of the purchase cost.

Anything is possible and I prefer the Ford 7.3 OBS for it's lack of emissions hardware and long engine life (typically 250K plus) for a non chipped motor with reasonable care and regular oil changes. The HUEI Navastar 7.3 is a bulletproof motor. Your issue will be the chassis. The running gear (Corporate 10.25 full floating rear and Dana 60 full floating front are also very overbuilt. Frame rails on OBS trucks are prone to excessive flexing but that can also be reduced with some added steel in the right places.

One issue with a standard box in an OBS truck is the hydraulic clutch actuation. Ford employed a fixed displacement slave cylinder with limited travel so clutch adjustment can be an issue. On my previous OBS, I had to machine an adjustable intermediate to achieve proper free travel. Why I went with an automatic on this one, that, and I had shifting gears anymore.