Just built the exact same thing myself so I wouldn't have to cut my t/b or controller harness'
I don't have the part number, but I can run it down for you hopefully. I sort of 'borrowed' my supplies from my work, for testing purposes

I believe most of our parts come from a company called kimball-midwest, if that helps any, but I'll check with my tech tomorrow.
On mine, I actually had to find the six-pin molex and then find the female pins themselves separately as the standard ones didn't quite fit right.
If there is anything like an Auto Safety House in your area (light bars, beacons, sirens, stuff for police/fire/city cars etc.) they should have something or be able to point you to it locally.
D13