I would consider the JRSC kit for the SVT. They actually just came out with it as it is specific for the SVT. I like it because it is just a mild boost, reliable, affordable, and wouldn't need to beef up the car very much.
Sure they have some more SVT kits coming out that are far more powerful but I am not sure if I am ready to beef up the whole car. I will see what is going on when I have the money saved up.
I do go to the Focal Jet and a few other sites.
