Shocks which do you have and why?

My Ford OEM shocks lasted less than 80K miles. I'd start by disconnecting one end of the rear shocks and cycle through its movement to see how worn your current shocks are. Mine still had compression dampening but rebound was gone. I went with the adjustable Rancho RS9000XL on my SRW because there were times when the truck was used unloaded. If I was always using it loaded, I would have used the simpler Blistein 4600. I think either model will work well and both have lifetime guaranties, so you just need to decide if you want adjustable dampening or fixed. There are other performance shocks on the market, but these two seem to focus on controlling heavy loads.