Do you guys know of any Auto Shops that dose Rear Brake Conversion Kits. Replacing my drum brakes to disc brakes on a 98 chevy cavalier in Milwaukee,WI.

Before you go spending quite a bit of money, why do you want to do the conversion? If you have done very serious upgrades to the performance of the car, then I can sort of understand. Otherwise, it is a lot of money for a cosmetic upgrade. On a front wheel drive car, with over 60% of the static weight on the front wheels, your back wheels are doing about 15% of the braking. If you are able to push the brake pedal hard enough to engage the ABS on dry pavement you will not get any benefit from rear discs, as the tires are your limiting factor, not your brakes, when it comes to stopping power.