What dyno are you looking to make your #s on? This is the most important factor in recommending something like this. There are dynos that stock STi's dyno 245+whp, and there is one in NY that they don't break 200whp on.
At 500whp, reliability as a DD is really iffy.
If you want a 500whp DD, you're looking at probably a GT35R (or larger) on 93+meth / E85 with a built motor and cams/headwork