I want to install a stereo for my motorcycle it's a loud harley so I need good clean loud music I'm looking at 2 ohm 5.25 infinity kappa 52.7i speakers rms power range 2x55watts peak power handling 165 watts and also want to run a shark subwoofer rated at 4 ohms max output 100 watts I'm just not sure if I should run a 2 channel amp or 4 channel amp and how to wire it. also if anybody has any ideas on a good small amp that will accept a mp3 only thats all I want to run on this system. it has to be small