You need the Superhitch if planning to tow a 6,000 lb. or heavier trailer with a hitch extension. I believe that $450 for a double leaf set of Supersprings is the best way to upgrade a truck to handle the weight of a heavy camper - easy to install and nothing to touch or adjust or fail for the life of the truck.
Should add in the cost for an adapter cable harness and labor to install it in your truck. Add another $150. And a bed mat for the bed is important as well. And tow mirrors if your truck is not equipped with them - cost of $250-$400.