Actually the stock 06-07 brakes are what used to come on the STI. They are what came on the 22B which is a good bit faster than even a well tuned stage 2 STI.
At the end of the day, even the stock bugeye brakes are more than enough to lock up the tires. While pads/lines/fluid will give better feel, most people in an emergency are going to mash the pedal, and give or take 5 feet or less, the tires will be what determines how well you stop. IE there isnt any stopping distance to be gained by upgrading the brakes if you are on RE92s. Going to stickier tires will do more braking distances and help with handling (which will keep the car safer). If you are driving a WRX, and are on RE92s and you go beyond EM/Tune/TBE, you are wrong. RE070s are good enough to deal with it though. STI Brembos are fine for street driving of any power level car no problems, even in bone stock form. 06-07 WRX brakes are limited by the tires but are still VERY good. I actually prefer them to the brembos. I think they have better pedal feel.
Unless you are talking brake fade, which isnt an issue on the street anyway. In which case all you need is better pads, high temp fluid (ATE superblue, although that is whats in my Miata and FXT, is NOT high temp fluid. Its better than stock, but not by a ton. Go for motul RBF600 or something like that) and stainless lines and fade will not be an issue for anyone but the most hamfisted drivers.