Alternatively, you can get a 1 Ton dually, a 9.5 foot camper with a dry bath, a slide or two, and throw on a heavy extended hitch perhaps. Tow that jet boat with it's several hundred pounds of tongue weight, load up for a week, and feel a lot better about everything except giving up your 3/4 ton truck.
Some of us that have gone to 19.5 wheels and tires, Rancho shocks, air bags, sway bars, and heavy rigs have done so gradually. Being familiar with how your rig will handle when it's heavily loaded is a learning curve.
With what you are considering, it's pretty hard to not get close to 5000 pounds of weight, most from the camper, but then the boat too, and hitch, and distance behind the rear axle...
Good luck.