Need More Suspension Help

My problem isn't with the engine, but with the suspension. The rear spring is flat when the tires are on the ground and the car bottoms out at every little bump. I have been looking at Mid-America's suspension kits, the Stage 4 and the Street/Slalom system. (I figure the car's 27 years old...If the rear spring's shot, the rest of the suspension is too) Has anybody ever bought/installed either of these "kits"? Is there a better deal with somebody else?
Here are the parts, so nobody has to go look:
Stage 4: 360 lb fiberglass spring, Performance front coil springs, Adjustable strut rod kit, front and rear sway bars, rear spring mounting kit, upper and lower control arm bushings, heavy duty steering rods, and Bilstein shocks.
Street/Slalom: 360 lb composite rear spring, Bilstein sport gas shocks, adjustable struts, 1 1/8" frint anti-swaybar kit, 3/4" rear swaybar kit, 550 lb/in powder coated front coil springs, poly shock mount grommets, poly-adjustable smart struts, and monospring mounting hardware.
I'm not going to be doing any road racing, I just want the car to handle well (Which it DOESN'T now)
Any help/advice will be greatly appreciated.
Handles a little rough for a street car, rougher than a new M3. About the same as a Z51 C5. Will keep you awake. :D I drove it 600 miles over the summer with no kidney failure though.
-Steve
Check out some of these kits that I have. I also offer FREE shipping ALL THE TIME to forum members.
http://www.vansteel.com/index.cfm?fu...ups&Group=6000










