I agree with Payton you need a sub, it lets you "feel" the music.The pioneer Head units have a million different adjustments and are good for the money.If you are going to run four speakers and a sub do yourself a favor and get one 5 or 6 channel amp,phoenix gold makes some nice ones.It will give you some good power without stepping into multiple amps.To save cash a space you can one run 12" sub in mono.I like like JL sub they have a nice hit
Good luck