Intake, exhaust, and programmer are the big 3 to get. I made my own CAI, its in the DIY section here. Also Superchips will be the best programmer for you if you only doing basic mods. Once you get into other internal engine ones a SCT tuned by Hemifever will be better. Exhaust, just open it up and let it flow. I do not run a muffler, just from the cat back a 5 ft pipe, soon I will have my tips out the side in front of the rear passenger tire, used to run duals out the back.