I'm looking to install a new system in my 98' Altima GXE. Now, my question. Is it necessary to go out and purchase a 60 watt radio (Alphine CDA 7875) if I am planning on purchasing an amp (MTX Thunder Amp 4244) with four channels? Or should I just go with the Pioneer DEHP 4300? Also, I'm still undecided between the Infiniti 652I or the Polk EX365. What about a 10 to 12 disc changer? I'm leaning toward the Pioneer CDXP 1270 or Alphine CHA 1214. Okay, okay, last question. Should I decide to add a subwoofer in the future (a pair of MTX 10" T6104 with Q Logic enclosures), would there still be a need for a car radio with three sets of Pre-Amp Outputs?