doesnt really matter. you cant see the leveling kit anyways. Most if not all, just bolt on top of the strut assembly, so you dont have to take off the coil spring from the shock. I have the PRG one. Its billet aluminum, came with bump stops and grade 8 hardware. PRGproducts.com
I was sold on the bilstein 5100 adjustable ride heights (get' um next week). they have a link to an article on their website that talks about shocks vs. spacers and how they compare and work. I though it was a good read.