Hey there…not sure what your budget is, but I strongly consider you take a look at the (VERY gently used) Snap Outfitters topper that is custom built for a 19+ Ram 2500/3500 shirt bed. It was an OUTSTANDING camper for me, but I had to part with the truck.
I have a home built sits on a 6 foot 6 Ford F250 bed. It has 200 W of solar 100 amphere lithium battery on demand water heater, heater and cooked top. 2000 watt inverter. Waterpump. $13500