Wow. I am sorry I wasted 5 minutes reading this. I agree with what jimf42 says plus you should add the wires from the transformer in the street feeding your house :) The aftermarket power cable thing is pure science fiction when you consider the whole ecosystem.
Just make sure the wiring in your power cord is thick enough (14AWG - 12AWG). If you are concerned about noise, such as with a Class D amp, get a shielded cord. And no, they are not power chords, those went out of fashion in the 80's with the hair metal bands...