Getting ready to upgrade

[Jester4kicks]

Ok, after a very healthy tax return, I'm ready to have a little fun. I'm not going overboard since I want to leave at least SOME of my warranty intact. Right now I'm planning on tweaking the exhaust, pulleys, cold air induction, and a custom chip (since I'm in Denver and altitude is a consideration). I currently have a 2000 V6 and I love it, I just want some more kick

Here's where it gets tricky, I'm debating simply replacing my existing muffler with a flowmaster, or dualing out the exhaust. I'm also having trouble locating pulleys (steeda.com has something resembling a pulley but I've never seen anything else like it), and I can't find a cold air kit anywhere.

I'm looking for advice here, hopefully from others on the same path, or people who have already tweaked their 2000's.
Help!