one very common wheel you see on WRX's are the Prodrive P1"s. They are great wheels being only 2lb heavier a piece. They are very strong wheels, considering they are used on the wrx's in the wrc on tarmac stages. My wrx is silver so i went with the antracite 17's, i think thats the best color for silver. I love the look of gold wheels on a blue suby though. Beautiful!!

BOV- nothing really good there except the sound. If you do get a BOV, look for one that can re-circulate 50% back to the intake, if not i've heard 100% atosphere BOV's make the car run worse. I have a BOV on mine that re-circs 50% to intake, it seems to work great, i havent had any problems with it.

Also, tire's, dont buy Yokohama Prada spec2's they are noisier that truck tires!
Enjoy your new suby!