I only wanted to be able to control my ride height so I went with 8" bags that can go up to 12" in height, I installed a top cage to make the install easy, and just bolted the air bag directly to the trailing arm and bolted it on. I inflate with a schrader valve and it works like a champ. Cost less than $200.00
http://kieth.smugmug.com/Trucks/66-G...5_pTfv9bn-A-LB