As far as exhaust systems, I mainly deal with the Akrapovic exhaust system (either full exhaust or just rear section), and the fabspeed HFC's + Xpipe. I can however get you any exhaust you are looking for - just let me know which one.
The Fabspeed HFC's + Xpipe are normally $2450 and the Stage II tune $1490 which is a total of about 4K. If you buy the package I can knock about $600 off which is a pretty good deal.
Full Akra system will run around $5700 which is a lot cheaper than I've seen around here.
Many of our customers are concerned about their new car warranty, and how the Powerchip will effect it. Often dealers give customers the impression that the warranty for the vehicle will be made void if any modifications / improvements are made.
Because this is obviously an issue for concern, we have designed the system so that you can still enjoy the potential of your car and have fun, without anyone ever knowing you have made the change. We can achieve this by making the Powerchip so that it appears 'electronically' the same as the factory programing. This means that the diagnostic equipment used at your local service center cannot detect that any change as been made, and thus your warranty is totally covered.
One of the best things about the Powerchip is that when you have the car serviced, the dealer cannot find your chip in any way. Generally, the dealer will run a diagnostic check over the vehicle, to see if any faults or problems have been logged in the vehicles computer. The Powerchip will interact in exactly the same way as the standard chip, and will not alert the dealer of any change.
I have attached a dyno of a 335 for those interested. It's about a 60HP gain with massive increases in torque. Please contact me if you would like any more info! I hope I didn't miss any of your questions.