theres been SAS in track/kicks before. everything from toyotas front and rear to waggy axles to danas to just a samurai front axle with the stock rear and others. TT sells a SAS kit for the tracker i think?? also ive read about them having coils, coilovers, and even jeep YJ springs front and rear and 3 and 4 links and such. i dont have a tracker, and never wheeled one, but i plan on getting my wife one. i also plan to SAS it to fit some larger tires. from what "little" research ive done, i think a set of yota axles and jeep YJs will be the way i go when i do it. only reason.... i got the springs and can get the yotas on the cheap from a friend. would be a trail only rig for her, so not too worried about how smooth the ride is at 80 MPH.
hope this helps.... later man, and good luck!!