blk6spd

Was in need of some advise on hooking up an amplifier for existing speaker location for a louder sound. Ill be replacing the fronts with an MB Quart comp. set, a coax for the rear door, and haven't landed on a rear deck speaker but am open to ideas. So ill be keeping the factory headunit so I need LOC or use the speaker level inputs? ive looked at a few things and read about the harness that I cant seem to lock down yet and I guess this is where I was wanting the advise. What amp is recommended for this application and do I need to purchase a Audio control lc6 for better sound Q? if im purchasing a good amp.