I need a good amp for my system

Aizen Sosuke

Hey guys I am very confused when it comes to selecting a capable amplifier for my system. I have the base 370z with the sport package and currently sporting a kenwood ddx-419 HU with polk db6501 component speakers. It sounds great but I would like to improve a bit on it by amping the 6.5 polk woofers and perhaps adding a small subwoofer to the spare tire enclosure. I was looking at the kenwood kfc-xw1000 because of its shallow mount size and specs. What amplifier would serve me well for these speakers and subwoofers? I am guessing a 4 channel and was looking at Alpine's PDX-F4, Kenwood's X600F and even JL audio's XD400/4. They are all CEA-2006 compliant and tested at the same voltage (14.4v) but I'm not sure if they are a good match as far as power for my speakers, and frequency and noise distortion. I need some input on these or any other you guys might recomend. I am looking for clarity in sound not the ultimate loudness and I definetly do not want my entire car rattling. Also if you have a better sub in mind by all means say it.
Thanks in advance