It's a pretty common 3-prong IEC plug. Any computer power cord would do the trick.
Radio Shack, Staples, Best Buy, etc. should have them. Usually 6ft long. It doesn't have to have the angle connector on it.
Here's one from Radio Shack:
http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=61-2860
I'm sure they have it in black too.