Don't run the wire that way. Once you glue down the mount, how would you ever change/remove the servo? Servos occasionally need to be removed. Just make a litte natch along side the servo body that the wire can snake out of. I am assuming that you planned to glue down the mount plate.

I forget what color you need, will any of these work OK?
http://www2.towerhobbies.com/cgi-bin...nt&FVPROFIL=++

There may be others available from other dealers.