I got the shock upgrade. They sure are stiff, and the ride is definitely stiffer than before. I also got the boots. Bought 4, but you should only buy two (you cant see the rear shocks so theres no need). I did not buy the stabilizer or arm and I am doing fine without. If you are doing this yourself even with moderate experience and a buddy, plan on devoting 7-10 hours unless you have an impact gun.