One can add all the popular suspension modifications to assist in weight carrying, but in the end, it is still a 1/2T vehicle. It still has inferior drivetrain components and brakes when compared to 34/T trucks and heavier.
This is a main reason why in my opinion the 150/1500 series are not well suited for CARRYING heavy loads. One does not want to break an axle on these limited duty vehicles... and braking (as in a panic situation) with heavy loads could be dangerous. JMHO.
If using a 1/2T pick-up, then maybe some of new cabover-less campers such as the Rayzor or the NorthStar Vista would be a better as far as weight concerns go.