everyone seems to say the sub.. so what is the best bang for the buck.. SVS or HSU or ep500?

why I wanted to change the amp, it's missing HDMI for the pvr & 3d blu-ray


7.1.4 * MRX1120 * M100s * 180HP * 4x M3-on walls * 4x M3-IC * dual XV15se * Shakers