Well after several months of not deciding what I want to do for the next mod...
I decided on a one piece aluminum driveline.
I got the Fidanza 900 HP Aluminum 3.5" piece. It weighs in at 17 lbs versus the stock 43 lbs. For the guys that don't know about the 05+ cars, the drivelines are two piece, heavy, and crappy.
I am hoping for a little better performance but also will like the safer aspect of this shaft.