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.
Too bad I'm still under warranty or I would get the OR and get it tuned.