If your trying to get your saggin rear back up, air shocks will give you a rough ride. My first car, a black 73 Challenger had them, of couse jacked up as high as I could on Fridays and Saturdays, G60s and cherry bombs off the collectors. Whew that was loud.
Have any of you looked at the Rancho RS9000's? I was looking at them a while back (I used to drive jeeps) and they look pretty slick. They have a kit with a compressor for the front and rear hooked to a set of guages and controls you mount under your dash and adjust the stiffness while you drive.
I went through there catalog and found the ones that fit our cars if anyone is interested.