The LS3 six speed manual does come with a full xpipe. GFX stands for ground effects. If you have the factory ground effects the normal 4" tips that comes with this system won't fit. You would want part 14951 if you don't have the ground effects package.
All 5th gen Camaro packages come with the sport mufflers which would be slightly louder then your touring set up. If you want it a little quiter you can always try the automatic version which has extra resonators on it. It'll fit just fine.