eBay seller "winterlamlam" is where I got the Cathode kits. If you contact him directly he'll give you a better deal on multiple kits.
To run the wires first you need to drill a hole down the center of the hilt and then another smaller hole (did mine at an angle, makes sliding the wire through a bit easier) on the side of the hilt. This hole is hidden by the palm when the saber is in the hand. Then "simply" run the wires up the sleeve and down the back of the robes.