Having been down this power cable road for a while now, I have had an evolving opinion as to how much is worthwhile to spend to get the optimal power handling and SQ benefits. So having prefaced my recommendations I would recommend any of the following:
1. The top of the line Pangea power cables, especially for amps. Their top of the line cable comes with one of the largest gauges of conductor that is out there at a reasonable price. Plus it has presumably good quality Cardas copper.
2. Shunyata Venom
3. No disagreement with Zavfino.
4. DH Labs PowerPlus.
I am sure there are others.