A camper on the back of a quarter ton pickup is a really bad idea. These small trucks are made for going to Home Depot, carrying mountain bikes and going to the mall. I am a firm believer in Toyota quality and have owned multiple Toyota cars and trucks over the last 25 years. With the exception of a RCLB Tundra, there isn't a single Toyota vehicle that is suitable for an integrated camper when you account for gear, people, water, fuel, storage and the like. The handling, braking, fuel mileage and capabilities will all suffer drastically. Try to stop a 7,000 pound Tacoma on a gravel road from 35 MPH with factory wheels, tires, brakes and a 7 foot tall camper on the back and let me know how that works out.
I laugh my ******** off regularly at the foundations of most of the builds I see: 50,000 pound Class A trucks, 8 foot (floor) campers stuck on the back of a Gladiator, triple cab trucks with 10 - 12 foot boxes and 170" wheelbase, high top Sprinters with 6" of wheel travel and about the same in ground clearance.
Where are you going to go in these vehicles? If you want to go off road, truly off road, buy a vehicle for that and carry what you need to support yourself when you get there. If you want satellite TV, a king sized bed and an oven, buy a Newell, Prevost or Marathon coach or rent top notch accommodations wherever you chose to go. You can travel there by car, truck plane, bicycle, bus or boat and have lots of money in your pocket from not buying a $150,000 - $750,000 "expo" rig to drive from one National Park to another.