Funny, I am in such a similar situation that I wonder if we are working on the same pitch.
We are trying to find an occulus-rift type device, or perhaps precisely an occulus rift, that can be rigged onto a shoulder mount camera. The thinking is that the camera would feed into a live keyer, which would be comped over a video game engine environment. This part is completely in theory right now and I haven't explored that world yet.
My thinking thus far has been to feed it into the Unity game engine, which C4D apparently supports now. So... now I am doing tests to see whats possible in terms of set design when outputting to the Unity game engine. After learning Unity a bit and seeing what type of end-quality we are dealing with, I will move onto how to get the camera motion into the video game world.
ni-mate looks cool, but it seems to only capture and record character movements. We are more trying to place live action people into a 3d world through a live feed. Bookmarked, though.