I am looking at buying a great used C300.2 from a buddy at work,it is in perfect condition, it has the original box, testing cert., packaging, and users manual. The only problem is it a 2 channel. :( I am looking for the 4 channel amp to run front and rear speakers. I already have 2 500.1s for the subs, just need 4 outputs for the full ranges. Anyone out there can help me with this?