I will completely disagree with the other posters. In just about every case, I've heard improvements placing a superior, higher-quality power cord on a motor controller, even the much-touted Brinkmann tubed power supply. It's a matter of improved conductivity and more efficient power delivery, ergo, higher performance.
The best thing to do is try any number of used cables offered here on Audiogon (and new ones with a reasonable return policy), and find what suits your system. This will reduce the risk of paying more for a bad choice, and you can resell quickly for the same price you paid.