My personal favorite sub brand is elemental designs. Their website is edesignaudio.com. There are a lot of good ones out there, though. Fosgate, Kicker, JL, whatever, but I'm partial to eD. I saw where Sonicelectronix carries Resonant Engineering now, which is a VERY good brand and prices weren't bad either. You could get a single 12", a class D amp that puts out 200 or 300 watts and it would be enough to melt your head.
2013 Race Red GT/CS 6MT; Elec Pkg; RAAMat on the doors; Morel Tempo 5x7 coaxials; GT500 axle-backs painted black