I buy a roll of Sullivan S-108 Tuf Strand U-control cable at my LHS. A 60' reel will last you a long time. See this link: http://www.sullivanproducts.com/Cont...eMainFrame.htm

The way I use the Kevlar allows it to be used without having to go in a perfectly straight line. I run the red nyrod outer jacket from front to back in the normal manner. I then put the Kevlar inside the yellow inner push rod and wick a small amount of thin CA into the push rod at one end only. The nyrod acts like a bearing. No chafing. Probably last longer than the model.