ya, i got borla headers, and i can tell you that the most thing u will get out of it is the sound. makes a nice rumble and stuff, but very little if any power gain. as for a catback made for a wrx, i believe the only thing u can use is the muffler because the midpipe is shorter on the wrx compared to the rs (correct me if im wrong). just get a custom midpipe (its cheaper anyways) and watever muffler you want. my whole cat back cost me about 300 dollars (custom midpipe, apexi resonator that was cut off from a different midpipe, and apexi n1 muffler). of course, i got the muffler from apexi garage sale, so i got it for a cheap price.