First, welcome to the boards! I also have a 2009 GT, so - have fun finding parts. Lowering springs, brakes, throttle body, headers.. all go up to the 2008 but not 2009 (i'm not adventurous enough to 'try' them first) so please, keep me updated on what you find.
On the boards here I've been talking with Lampoon, he makes the CRAB intake which truly is your number 1 solution for intakes - little over 350 for the full setup so it is pretty expensive but I've been trying to have him make me one myself - I think he's been busy, have not heard back in a week or so but once i find the details I'll let you know.
The GT-R exhaust appears to be the best option for our cars, not outdated just yet haha. My issue is from what I have heard/seen they have some back pressure issues but I have been told the excessive crackling and popping is nothing to worry about. Needless to say I have not put one on yet, but I also have the 4door - not exactly the hot rod LOL.
As I said, welcome and keep us (pm me!!) updated on what you find.
David Hall - 2009 Pontiac G6 GT Blue 4-Door
Performance: CRABS 03 and FPU, Resonator Delete, RL Strut Tower Bar
Appearance: Debadged - Window Tint 35% front 18% back - Emblem Overlays - Door Sill Overlays