you need to replace the springs and shocks with shorter ones, however you might have a problem with the rear end of the car because of the torsion bars.
Check out
http://www.renault-tuning.com, they have a tutorial on how to fix that
As for racing parts, I'm looking into it at the moment, I found this Renault tuning shop and the guy told me that he as some parts if I'm interested. I'll check them out and let you know
