Here's some places to look;
For flat AC Cords:
[Link: hosfelt.com]OR:
http://www.cyberguys.com:
POWER EXT CABLE, 8FT, GRAY
search for #113 0850
also at cyberguys:
PHONE, FAX & POWER EXT, 8FT, GREY #113 0845
CABLE SAFETY STRIP, 6FT, GRAY # 113 0835
CABLE SAFETY STRIP, 25FT, GRAY # 113 0838