Check into GTworx/RCE These guys will not steer you wrong and there are literally a ton of people running their regular guy and yellow springs.
GTWORX.COM : GTWORX/Bilstein Impreza WRX Cup Sport Kit
There are wrx kits available, just aren't on the website yet. Catch is they wont be in stock until first week of dec (according to a recent email I got from them). I plan to run the regular guy springs (270lb/in front and 250lb/in rear) for a nice streetable setup that doesn't take my teeth out or shake my kidneys loose. If you're going to track the car.. the yellows are the way to go. Those are 330lb/in f/r and both the regular guy set and the yellows are the springs that Bilstien used to design and valve the struts for the GTWorx folks.