You could look for parts off a 9c1 Caprice (cop car). If you're not you are looking at a cop car, look at the RPO sheet and look for B4C on it. That is the RPO number for police package.
Here are some brands to look at Hotchkis, Energy Bushings, BMR, UMI, Addco, and Moog.
Here is some suspension parts and some are performance parts.