Planning on using an AudioControl LC21 and running an amp to power the rear speakers and a sub/subs. I'll let the radio power the dash speakers. What kind of amp, channel wise do I need? And power wise. Don't need crazy loud, just better than what I have now. Of course, I could skip the subs and just use an amp on the rear speakers. I'm using an early 90s Delco CD player w/5 band eq. Any thoughts??