I would wait til you get your header/downpipe setup before the tune, otherwise, youll have to order a re-tune and spend more $$. Trifecta is good for just a basic tune for all climate conditions and altitudes. If you get one around your tri-state area, it will benefit far as Horsepower goes, but I would say Trifecta is decent enough.
2009 Cobalt LS XFE U74
Mods: K&N Typhoon Intake, Option Cat-Back Exhaust, Cosmo Short shifter, Maxxim Ahead 17X7's, MPx shorty antenna, FE5 Strut/shocks, Tein S Techs, Moog endlinks, Moog spring seaters, ZZP shorty header, LSJ downpipe, LNF front grille