I would say get yourself a crossover, and a 4 channel. You gotta make sure you seperate the lows from the front speakers since they are 6.5. Since you dont have a sub, you will be pushing as much bass out the speakers as you can, so you want the front speakers to receive less lows thats the rear. It will sound nicer at higher volumes that way. 2 channel you would have to bridge the front speakers and the rear speakers as one, which means stereo wouldnt sound as good. The setttings for the front speakers have to be different than the rear. Even better would be to get a crossover and 2 smaller amps, that way you can fine tune even more.