Dude:
If you spent a lot of time in the S-chassis scene, then the Evo scene will be no different other than the platform itself. You will need to learn about the car (if you haven't already), and shop around everywhere you can for the parts that are right for your taste/goals in terms of quality and budget.
Very important: Get on an Evo forum... actually, get on a few. The way I see it, THOSE are the folks who will tell you the best places to go for good stuff at good prices.
Asking this on a forum ruled by Nissan enthusiasts will not get you very far
