Foam Cutting Wire.
I was browsing through the fishing section of the Boat USA store here in Port Charlotte yesterday. They had a package of 42 feet of 0.02 stainless steel fishing leader for $2.39. The coil is about 7 inches in diameter so when it is uncoiled, it will be completely free of kinks. This is the same stuff that I have been using under high tension for the last 10 years or so without ever a breakage or other problem. The Manufacturer's address on the package was Malin, 5400 Smith Road, Cleveland, Ohio 44142.