Go to a 4.10 gear or bigger
then there's a power programmer from Bamachips for $400 that will give you a few horse, and they help the low end, part throttle, and over all driveability. You can get an under drive pulley from rouge (sp?) performance for $80 and they say its good for like 8 hp, I dunno but I only hear good things about them and how they help alot across the whole rpm range. Then you can do Roller rockers for $250 that are good for 10 hp I think
As far as a CAI or cat back exhaust there really no power to be had there, JBA makes headers but Ive read they dont do anything. Electric fans are junk, all the ebay stuff (Intake temp sensor resistors, Tornado intake deals, electric supercharger etc) are all crap. Someone makeaas a cam ported heads and lower intake for the 3.0 but Ive never read anything about them and there big money.