Here are some pics of two brackets I had fabricated. They are simple angle stock with holes to mount the Red handle extension and the battery. I also had a hole tapped to mount the EVF arm. The reason for these brackets is to have the camera as light as possible, no top rods or other jewelery, just a handle, EVF, and battery. This setup with an Arri LMB5 made for a good lightish "I call the camera Lead, after a few hours of run and gun", single person setup. My intension was to use these as a prototype and have proper brackets CNC'd and anodized. But alas, I am a cameraman not a machinist and do not have the time to work on this project. I also thought that you could incorporate a v-lock into the rear bracket to quickly mount the battery sled. The other option I was looking at was an EVF mount that could be mounted on the end of the RED handle extension via the threads that are there for the top handle.
Here are some pics, please vendors go nuts, this is an easy way to get the camera light, and retain the stock RED parts.