Get a baja turbo for like $22k. Same basic engine as the STI, just detuned, need sti turbo, intercooler, and a few things to make an sti killer. All it takes is like $6k or so to get it up to nearly 400whp and still be under the cost of an sti.
http://www.xcceleration.com/xt-baja-turbo.stagekit2.htm
ag04