So, for the amp, would a five channel be sufficient to run 5.25" mids, 6.5" 3-ways, and 3.5" mid/tweeter, and sub? I guess the four channels would be adequate to run 6 speakers?

Also, I'm still kind of lost as to just how much power I need in the amp. Speaking in RMS terms, the 3.5's rate at 35W, the 5.25's at 55W, 6.5's at 75W (these are the high end of the ranges starting at 2W). The sub ranges from 75 to 350W RMS.

Again, I'm not going for tons of bass, and I probably won't be cranking it too often. So, do I need an amp to accommodate all of the high end RMS ratings? (2X35+2X55+2X75+350)? Or would a 40-60W channel power a 75W rated speaker well enough? Most of the 5-channel amps that I looked at had a dedicated sub channel around 100-200W. Any thoughts?