Piggyback will probably be fine. But I could be wrong.

For serious suspension fun, pick up the Progress rear sway bar. I loved that ****.

 

The piggyback works by making the car run slightly (key word) leaner. Its perfectly safe, the car runs ridiculously rich anyways so taking away a little bit of fuel is fine. Other options are a header, TB, IM, strut bars (front and rear), etc..