I've just been buying 12" wire strands with Futaba plugs, dying those and then soldering to the circuit board. I can get them to stay black rather than discolor after time, just takes some time in the dye. I'm just looking for a manufacturer that sells wire that's already black in bulk. I can put connectors on myself, that's easy with the right tools. I found a good deal on a Hakko FX-951 iron for $220, so I think it's time to switch over to one of those to make these projects easier as well.