Im really tempted to go wth the shorties but I haven't seen any dyno numbers or any improvements really broadcast yet. I think suspension will come first.
Give this some thought. The longtubes are very easy to install. Granted you will need a midpipe. ( I went with the high flow cats unit) I cant comment on improvements with the shorties, but I can tell you first hand that longtubes give a dramatic improvement in sound quality as well as a very noticeable torque increase. Before putting on the headers my car would barely break the tires loose from a dead stop ( mines an automatic with 3:31 gears) now it will lay a pretty good patch, if that what you want. And it definitely pulls much harder even in the lower 2500 to 3500 rpm range.
I know its a personal decision. Good luck.
2011 GT. Grabber Blue. Procharged. 3:73 manual.Billit LCA's. Corsa Extremes. GT 500 wheels. Racemaster DR's. T-56 Tremec. Dynotech DS . Centerforce DF. American Racing headers/high flow cats 560 rwhp.Donny Walsh tuned
2012 Pony Package. Race Red.3:31 automatic.BBK longtubes and catted X.FRPP Sport axlebacks. BBK throttle body. Dynotech DS. Brembo wheels and tires. Strut tower brace. Airraid CAI. Bama tuned.