You need the cherry bomb, the flow master, and depending on the install, hangers for the new muffler, piping (and bends), a new coupler to attach to the flex tube at the front, and probably two new exhaust tips. If you don't want to cut you're existing valance, you'll need a new dual valance. If you want to stick with an easier cost and install, just keep the stock 2.25" piping and just replace the resonator and muffler, and add the two new tips. Are you looking for part numbers and or links for the parts?
2009 Techno Gray Metallic G6 GXP Sedan (3.6L Auto6 112K miles)
CRAB Intake Opt 3 w/FPU, Lloyds GXP floor mats, HIDs low 6000k 55w/fog 3000k 35w, LED DRLs behind lower grills, V3 Triton LED turn signal/reverse/brake, LED side markers/maps/dome/tag/trunk/high mount stop, 2 coats niteshades on tails, Tint 35% all around, Debadged (except arrows), PAC IPod and BT adapters, PowerStop D/S rotors and ceramic pads, Resonator repl w/24" cherry bomb, Racingline STB, Big 3 Upgrade, Optima Yellowtop D75/25, Blacked out arrows, chrome window trim and black dipped wheels, KYB struts and shocks, CM lowering springs, Cherry Bomb Vortex Crossflow muffler, 2.5" pipe from axle back, two 4" stainless double walled slant tips