I am looking to buy a HDSLR as an entry into filmmaking, I wanted to not buy a lower spec camera first but actually go all out and purchase a model with a full-frame sensor.

I found the Nikon D600 first and looked at the quality of video that can be produced and learnt that this camera has so much potential. I then learnt that the D610 was released as there were a few minor faults with the D600 (dust/oil on sensor), they also made a couple minor things better but they are 99.9% the same camera, D610 being the faultless model.

I then was told by my friend who is biased toward Canon anyway, to check out the 6D. Both of these cameras have full frame sensors and are brilliant for film making. The Nikon would be better for action shooting (photos) but there really aren't major differences between the two. 6D has wifi and GPS where the Nikon has a pop-up flash, 2 SD slots and also a headphone out port unlike the Canon. Both cameras work well in low-light situations, the Canon able to reach a higher ISO. I was also told Canon should have the advantage for video as they have apparently produced cameras with video capabilities much longer than Nikon have.

What I would like to know is in the long run, which camera is better and more suited for filmmaking and why? Is there an equal amount of equipment available for either? Is there any other model of camera in the same league and similar price? The Canon I can get for 100-200 cheaper, but that isn't a bother as I would rather get the better camera. (Though I won't stretch higher than 1,200 absolute maximum)

Both similar price, but diving into something like this I would like to try and find a clear winner. All help appreciated, thank you.