most components are power hungry. from experience, polks work well with the polk amps and alpine's i have the polk momo comps running off an older model alpine amp and they sound amazing.
would it be better to get a 2 channel amp for just the components or should i get a 4 channel amp to power the 6x9s in the rear? also if the speaker's impediance is 4 ohm does that mean i would have to run an amp at 4 ohms as well or could i run it at 2 ohms?