check out the website for www.myhps.com. You can get a supercharger for around $7000 to get you in the 400HP range, if that's what you are looking for. Good Luck
There really isn't a way to tune that car to make 400 more HP out of it. Think about it, the car is only 275hp Stock. How can you get double that amount out of it? The best you can do is probably get it up to the 400 range. But nothing more than that. Good Luck