exhaust for 03 Gixer, most power and nice sound?it worth it?

Hey guys, I have an 03 Gixer with a yoshi RS-3 Bolt on, and I am wondering if a full is worth the money, I am very happy with the bolt on but looking for a full system, I have heard that the header on the newer bikes are just as good as the header w/ the full system and arent really worth it!? This true??? Also any suggestions on top performance exhaust and something with a good,loud sound to it, I like that Formula car sound, something high and high speed. Also any suggestions for small power upgrades? Should I go with high mount, or mid?? Lots of questions, need lots of help with decisions, thanks everyone.