Based on your components, I would try Audience powerChord. These should also do good on the amplifier. You should be able to determine with these power cords what they do and do you like what they do. they can easily be resold.
Are upgraded power cables really worth the money?
My system consists of musical fidelity a5 integraded and cd player, b&w 703 and a rel 305 sub. I'm Im using purist audio musaeus interconects and speaker cables. I understand and can certainly see how these cables have helped my system, but am a bit aprehensive about investing in upgraded mains cables. Do they really make much difference? With the system I have what would be the right amount to spend on them. Any suggestions?