If you want a CAI go for it. It will sound different and give you better throttle response. Its usually one of the first mods people do. If you have a good amount of money go for the LMI Hammer intakes. If not, really any will do. I have the K&N which some say bad things about but it works. It comes down to what you can get a deal on.
As for exhaust, look at the Blastin Bobs' reso deletes. They are cheap and effective. They will give you more sound and take out the restrictive part of the system.
If you want another fun mod, check out the Tranzformer.