Leer Cap Install Wiring Question

I just picked up a Leer cap this afternoon from Craigslist. Bolted it on but now I have two questions. First:

Where can I find a connector to match up with the wiring harness coming from the cap? I have the cap side of this connector that leads to the 3rd brake light and LED light, but I need the other half of this connector to tie into the driver side brake light.

Below is the part that I have. I need the other half of this. And directions as to what wires I'm tapping into.



Second: I noticed that the rails of my bed have plastic guards on them, but the front of my bed (facing the cab), sites about a half inch lower than the sides because the front does not have plastic guard. Am I missing a piece for the front of the bed? I'm thinking this is going to leak here.

 

Old but I need a answer to how to wire the leer also.