I'm pretty ignorant about everything I drive a 2003 Honda Civic coupe and have Boston NX67's in the front of my car and NX97's in the back. I want an amp to make them louder but mainly clearer and I have an Alpine CDA-9833 headunit. I don't know if I should get a four channel amp or two two channel amps. I was thinking about a PPI DCX 600.4, but have also been considering Alpine, JL, and Soundstream. Is there a brand that is a clear cut winner and how many RMS watts should I look to get for each set of speakers. I also have a 12jl w3 sub with a ppi pcx1500 if that makes a difference. I appreciate the help and please explain any answers you give so a layman can understand.