To get true end-to-end 10bit support you need a 10bit card that's connected via DisplayPort to a display with 10+bit internal processing (LUT, transform, scaler) and 10bit panel (very rare and expensive) and then a wide enough gamut to make use of the expanded colorspace (again, expensive). Getting it in a 4k package would likely mean $2k+ at this point. And then you need 10bit content for all that, which nearly all games and a majority of videos aren't. If you shell out 2k+ for the display, you can squeeze your ass for another $100-300 for a 10bit capable VGA, even if it's to be a secondary one just for video playback.
Video editing pros and photo editors aren't going for a gaming card for that purpose anyway.
It's much too early for 10bit, and the 960 isn't suited for 4k (except maybe video playback, but even that's questionable at 50+Mbps with postprocessing).