I would bypass the factory amp and run a 4 channel or 2 channel.. if you doing 2 sets of the comps I would get a 4channel if you just doing the front just get a 2 channel... something that would do around 50-100rms at 4ohm should be plenty good man... check the classifieds prolly can get one for under $150 .. something good anyway maybe even $100dumb question do i have to get like a 4 channel amp or will the factory amp work fine