Planning Revo V2, to use stock tranny, C. diff and RCM motor mount

Finnster, I am going to be attempting a similiar conversion on a used revo I recently bought.

I have been struggling with how to set up the tranny though and wonder how you plan to be able to use a single channel on the reciever to make your esc work when you pull the throttle trigger back and yet make it controll the servo for mechanical brakes when you push the trigger forward? I can't figure out how to make that work and I can't seem to find any info on it or even a different way to do it.

I would really like to retain the mechanical reverse and brakes on my revo tranny so that I can keep the two speed functional but I am stuck on the issue I asked about previously, how do you controll two different items with a single channel on the reciever?