You are probably better off with the Tokina and a speedbooster, Nikon F to MFT.
I use both the GH2 and BMCC 2.5k with Zeiss glass, and a speedbooster. My images appear sharp and bright, while still encapsulating the venerated Zeiss lustre and luminosity. I noticed a fair bit of grain in the test video, and the images were soft. I am not sure if they will hold up on the big screen