http://www.acp-composites.com/acp-cord.htm

What you want is .038 Kev-Cord and the Kev-Cord Connector. Even though they describe the supplied items as crimps, don't crimp them, there is no need if you use them as I described. The connectors are what is shown in the photo. I use the crimp thingys at the servo end and the bolts at the rudder end.

Craig.