Im with Ian.
Save your cash for a turbo for when you can drive it.
Max I'll spend on my N/A is 2.5-3g's...exhaust, cat, turbo brakes and maybe some nice rims.
However if you got the cash, I estimate you can get a good 130-135rwkw without opening the engine too much?? Exhaust, Cat, Extractors, Adj Exhaust cam gear (~retard 3 degrees??), new fuel pump (if yours is dying), an effective Pod and CAI setup or high peformance panel filter, and some good quality fluids. New bits and peices here and there.