If I didn't go for a high flow, i'd get a KKR. They're not ball bearing turbo but they did say they would warranty track use. Otherwise a ballbearing turbo, they're expensive but they are soo much nicer. Unfortunately, no warranty for track use (if they find out).
I bought a pair of R32 wheels for $60-80, i forget. I wouldn't pay more than $200. 2nd hand tyres are generally free to $10. If they want money for the tyres, check the age, if it's been weathered and the brand.
Don't know how much coilovers would be worth, depends what you get. Becareful with 2nd hand, make sure you check the shocks are not blown or leaking. Check joints for noise/seizing. I would pay around $600 for second hand. New HSD's are around $1400-1500.
SAFC, isn't too bad, but doesn't compare againsts a full computer. You could even get a nistune chip tuned for the higher boost you run, what ever you set it at.