Rockford fosgate has some pretty sick 8" subs. I wouldn't go any bigger then 10's though, smaller subs will hit faster, and with the double bass in metal it'd be a better bet. Are you lookin for something that is gonna be rediculous? or just to add to the sound? I have a rockford fosgate amp I will sell you for 100 dollars :dontknow: I know its a competition amp, I can't remember what class, but I beleive it's a 1400 watt. Back when I used to listen to hardcore it worked great for me, but I mostly listen to country now, so it'd be a waste in my car lol. PM me if your intrested man