It's pretty much a given that you will have to upgrade the receiver on the truck, if it is the factory receiver. Extensions will severely de-rate the capacity of the factory receiver.
Factory receiver likely has 500 or 750lb weight-carrying capacity, and 36" will cut that by 2/3. Personally I just wouldn't feel comfortable.
About the only extension system that I know of that comes complete and ready-to-use is the Torklift Superhitch.
Reese makes some extensions that work with their "TITAN" receivers, but no stabilization chains and nowhere to attach them. They leave that all up to you, and provide no guidance (presumably to limit liability). All you get from Reese is a piece of box tube with safety chain loops welded on.