Probably can buy a good trailer for cheaper and be able to move it with your 1/2 ton if needed. That’s likely going to be required to dump assuming you use shower/water/toilet. If you are using a casette and not the shower or water, it wouldn’t be required. I wouldn’t personally buy an RV that I can’t move. You could also put a truck camper on a trailer, but you have to make sure the trailer will hold the load.
Back to the original point, you can build supports out of plywood, etc to support the truck camper while off truck and just lower the jacks down to the supports. There are a few designs here if you do a search in the archives or a general web search.