For intake Mods, get your air filter from WeaponR.com in South San Francisco, and put it on the intake system from Adam of Prototypepower.com in so Cal. He'll ship the kit up to you and you can install yourself, it's not really that hard, bolt-on stuff.
Any good muffler shop can install the exhaust system of your choice, see the forums for what people have and what they like.
Then see Tommy Thrift of HaynesSpeedShop on these forums for good tech advice for the rest and you should be on your way.
Natasha
Team Nexus
http://www.teamnexus.us/members/natasha