Ummm...headers = exhaust...catback does nothing...save your money.
Cam OR rockers.
Unless you plan on getting a VS/XP/S1X and offsetting the ratio somewhere with 1.70:1's instead of 1.60:1's.
Just get a S1X or XP if you plan on camming...but since your saying you want to do cam and rockers...I recommened researching and reading as your first mod after headers.