To tell if your truck needs new shocks, push down hard on the bumper and let go. Do it front and back. The truck should go down as you push it and then back up. If it bounces up and down more than twice, you need new shocks. As far as what kind, I think that's like what kind of oil to use...there are many different kinds, and just as many opinions. Honestly, if you need new shocks, any one will be a real improvement to your truck. I have heard good things about the Bilstein, but I can't say that I know myself. I went with the Rancho's because I do quite a bit of off-roading, and I really like the red and white with the matching piston boot. Good luck with your decision.