Trying to get my civic sounding better.... I'll be running Polk Audio 651's and Polk 6500 compoents. Need a clean 4 channel amp to push these, around 75w x 4 @4ohms. Any suggestions? I like the idea of keeping the Polk theme goiong but not sure about their amps so if you have any knowledge on them i'd appreciate it... Thanks in advanced. My budget on this is under $150 if possible.