Try the DuBro coated cable set in 4-40. Making the fuse penetrations with plastic tubing like NyRod housing, perhaps through small blocks of plywood is a good idea, but if you run straight uncoated cable, it will cut through the tubing in the fuse. (Small cable makes a great plastic pipe cutter) The DuBro is probably your best bet and plastic on plastic is much smoother than cable on plastic.

I just finished the elevator and rudder cable penetrations on my Nieuport in this manner. If you want a pic I can snap one for you and post it.

As far as interference, most modern up to date narrow band radios should be unaffected, unless you have uncoated cables rubbing together, which is not good in a pull-pull anyway.