i would first say that a track event or two would be the best way to get your feet wet. as you mention, you only daily drive the car. it's quite possible that you have not tasted your cars' full potential. participating in such an event would allow you to become very familiar with the limits of the car; which i'm thinking you already know is high.

once you've seen the cars' capability in stock form, you can make judgement as to what type of modifications to go with.

i personally found that at my level of tracking ability, the stock suspension was more than adequate. i decided on upgrading the exhaust system; jdm sized header (2.5" collector), jdm length cat (must be changed out to fit jdm header application), matching b-pipe and exhaust/muffler. in addition, the other simple upgrades such as adding a rear upper strut bar.

it sounds as though you've got quite a lot of money to spend on the car ($2k/year). take your time to choose the best parts for your needs. also, pick quality parts as well. there are a lot of great products out there with an equal share of bad ones.

good luck!

kepani