again, i'm in the same boat lol.
i know there are JB4's out there, but i don't think they have been officially released to the public.
as of now, wether you go JB4/V5/Cobb or GIAC it's going to come do to price.
the first 3 should give you minimum of 70-80whp just plugging into a bone stock car.
the GIAC is beneficial when you are already bolted on with DP's, FMIC, catback, etc.
the ProTuned Cobb is beneficial that way as well.