Tripp Lite offers 14AWG power cables of various lengths that should do the job. They're good quality, UL-listed with a lifetime warranty.
https://www.amazon.com/Tripp-Lite-Computer-IEC-320-C13-P007-006/dp/B0027JRMD0/ref=sr_1_5?dchild=1&am...
https://www.amazon.com/Tripp-Lite-Computer-IEC-320-C13-P007-006/dp/B0027JRMD0/ref=sr_1_5?dchild=1&am...