I use the 12 gauge, 2 conductor SJOOW cable from Carol cable. I get mine from Home Depot but I'm sure you can find it cheaper somewhere else if you look. I use this wire for speaker and power. (3 conductor for power applications)
I'm also with Bruce, just buy a bunch of NL4's and screw them on. You can't beat field serviceable with just a screwdriver.
If you're curious about the codes on wires here's the breakdown:
S = Service Cord (600 volt standard unless the J follows it...)
J = Junior Service ("junior" is 300 volts or less)
T = Thermoplastic outer jacket
E = Elastomer outer jacket
O = Oil resistant outer jacket (usually rubber or a synthetic variation...)
OO = Oil resistant outer jacket, Oil resistant conductor insulation
W = CSA weather and water resistant (approved for indoor and outdoor use)
Here's a nice website with general information the amperage rating for the various gauges of SOOW and SJOOW...
http://www.pittsburghwire.com/pdf/CatalogD2.pdf
Here's a long article on the use of portable power cords in the entertainment industry.
http://www.local16.org/safetycommittee/ ... essp02.pdf