Best DSLR mainly for video $2000 budget Gh3, 6D, D600?

Hello I am looking to upgrade to a new video camera. I have been using a hacked Panasonic GH1 and it has been a nice camera, but is getting a bit old and frustrating in run and gun low light situations and is not always reliable with the hacks. I am looking for a camera mainly for video as I am a film student and have been doing some videography freelance work. I would like to be able to take better stills as well knowing how the GH1 is not all that great at stills and even the entry level canons or Nikons have better looking still photos. But video is most important for my needs. I am having a difficult time deciding what would be my best investment. I like the specs of the GH3 and I already have the 14-140 m4/3 lens. The GH3 shoots 1080/60p, has an external mic jack, unlimited recording and time-lapse feature in camera. All looks great for a videographer! What I don't like about it, it does not have as good DOF control, I know DOF is overused a lot but its nice to have that option on more lenses. The GH3 also is not as good in low light as the others and it seems a little too sharp in some videos I have seen, giving it a more video look. Maybe post could fix that, but the GH2 seems to look more film like with hacks straight from camera. What the other cameras have going for them is the great looking images with the Full Frame sensor, great low light capabilities, better stills, and the name that clients and industries know and use a lot. Negatives of these cameras 30min record limit. No articulating screen but wifi to smartphone makes up for it on 6d. D600 I hear has dust problems on the sensor. They both suffer from Moire, but they all kind of do so in the price range I can't worry too much about that. Or maybe I need to dish out some extra cash for something else?