FYI
the WORX~Tuning guy is a flake. he is a complete hit or miss. very inconsistant. Hope it works out for you.
300whp is very easy to obtain in a STI.
reflash and turbo back from PDXTuning will give you that on a low reading mustang dyno
Stage 3 prices
EcuTek Reflash$799.99Perrin Short Ram Intake$189.99Perrin 3" Turboback Exhaust$1,039.98Perrin 816cc Injectors$639.99Totals$2,669.95