Performance springs usually always lower the car. The whole point is to bring the center of gravity closer to the ground for better handeling. In my honest opinion all your car needs is to be lowered about 1" and it will look amazing, you wont regret it. Plus its not your daily driver so you dont have to worry about scraping all the time.
The only not lowering spring I can think of would be OEM. GM Performance probably makes springs, or just go with the regular Eibach Pro-Kit.
__________________
|