Don't forget, if you are going 450HP, you will need to spend another $1000+ on a clutch that can handle it and that clutch will suck balls on the street.
If it is not going to happen soon, go for rides in April and feel what good drivers can do with well prepared cars. Cory's 150HP? RS will feel like 450 in the corners where it matters. And Matt's and hopefully my STIs will give you an idea what a well prepared 300WHP stock turbo will do and there will be others... Drags will be a distant memory once you turn and brake at 1G or so. OK, maybe 0.8G at Stead.