Get a CAI first. I just installed one today, and it's a big difference.
Love hearing that SC howl !

Kuhmo Ecsta SPT's are a good 3 season tire on a budget; probably around $700 a set.
I got the Nitto Invo's for better wet weather and light snow driving.
Really smoothed out the ride, and very grippy, but a bit of sidewall flex at high G; $800 a set.