New Truck Campers

I’d stick with as new a camper as you can afford. In general, campers don’t age gracefully in most respects unless you find a unicorn that is old and perfectly kept in every way.
BTW, we’re neighbors. Up here there are TONS of truck campers for sale. You should have no issue finding one that fits your truck and your needs.

And if your tires’ age or load rating is in question, consider takeoff wheels/tires from a newer Ram. You can find very nice new setups for less than the cost of comparable tires alone.