I would look into a Rockford Punch series 4 channel and run it bridged...You should think about buying the Infinity Kappa 60.7cs...It is 2 ohms so it will cost less to power it corectly. The THD on the amp will be higher than at 4 ohms, but only .05% higher which is not noticeable. I've heard better reviews on the 60.7cs than the 6.1 and it's cheaper. It is their new 2005 series. The 6.1 has been out for 2 or 3 years now.