You can check out the new Injen intake that's coming out. That's got a ton of people talking... Common intakes on the forum are Gruppe M (and it's replica), aFe, Simota, and Fujita. Watch the marketplace because those things pop up all the time.
As for exhaust- if you're just interested in sound, check out the muffler delete threads. Wonderful alternative to spending $1k+ on exhaust!