Best bang for the buck as far as adding HP is probably going to be a CAI and a hand held tuner. As for which one, man, just get the one that jingles your bells the most. Everyone is going to have their own opinion about which one is best and it will probably be the one that they own. Personally, I went with a hybrid setup on recommendation of a very well known performance center and I couldn't be happier with it.
As for the exhaust delimma you are having, once again, go with whichever one you like. Axle back setups produce MINIMAL gains on the S197 cars. So basically ignore ANY claims by manufacturers of gains and just get what you think sounds best to you. Yes you can mix brands on the components. I.E. one brand on axle back, one brand on mid pipe, and one brand on headers. Personally, when it comes to the mids and headers, I would stick with a like brand just to avoid any unforeseen issue of adapting them together, but that's just me.
Computer flashing is going to be an every step of the way thing. You add a CAI, you flash. You change gears, you flash. You add IMRC delete plates, you flash. You do major exhaust changes, you should get your butt to a dyno and check for a lean condition...and probably flash. I think you get the point.
As for the hand held tuner. I personally own a Diablo Predator. BUT... since you have an automatic tranny, I would probably recommend an XCAL-II tuner. It has superior automatic shift adjustment abilities ( at the moment ).
As for the exhaust delimma you are having, once again, go with whichever one you like. Axle back setups produce MINIMAL gains on the S197 cars. So basically ignore ANY claims by manufacturers of gains and just get what you think sounds best to you. Yes you can mix brands on the components. I.E. one brand on axle back, one brand on mid pipe, and one brand on headers. Personally, when it comes to the mids and headers, I would stick with a like brand just to avoid any unforeseen issue of adapting them together, but that's just me.
Computer flashing is going to be an every step of the way thing. You add a CAI, you flash. You change gears, you flash. You add IMRC delete plates, you flash. You do major exhaust changes, you should get your butt to a dyno and check for a lean condition...and probably flash. I think you get the point.
As for the hand held tuner. I personally own a Diablo Predator. BUT... since you have an automatic tranny, I would probably recommend an XCAL-II tuner. It has superior automatic shift adjustment abilities ( at the moment ).