There are several different options when it comes to air ride suspension. Most J owners choose strut bags for the front of the car, and air cylinders for the rear. While the ride comfort is far from stock, accumulators can help dampen the bounce (but let’s face it, most people consider air ride for the looks, rather than the comfort aspect!).
Complete bolt-in kits are available from Air Ride Technologies. Custom installations are available from many sources, including Underworld Customs. Several different manufacturers make parts for the J-body, including Air Lift, Firestone and Blowjax.
Hydraulic suspension is not recommended for a uni-body car. (Tube frame is a different issue altogether!) I am unaware of anyone with a hydraulic suspension on an otherwise stock Cavalier.
