GTR ally

I pick up my 06 STI on Monday and as its standard I wanted to get a new exhaust for it. I'm looking for some advise on what you guy have had experience with. I want a nice sounding system without being too loud. I heard that upgrading the panel filter was also a good idea. A decent BOV will also be on the cards so any advise based on experience will be gratefully recieved.

Cheers Ally