I don't know of any gpu that has hdmi 1.4 yet. For the price of that tv you could get three 2560x1440 monitors in eyefinity and still have a couple hundred left over.
HD7970 has an both HDMI 1.4 and DP 1.2 - that thing is very capable at feeding the display 4K /x 60 Hz - over the DP/. well, the problem with 4K gaming is, that you'll get 30 FPS on average (which kinda sucks). Also more than 4GB VRAM should be recommended...
Now, the Titan would be viable choice - HDMI 1.4a + DP 1.2 support, 6GB VRAM and a lot horsepower
But as long you're not gaming, those cards would be a waste
Also, on a side note - every GF6xx should have by default a DP 1.2 and HDMI 1.4a support, so it is capable of displaying 4K... Sorry, I don't know about much AMD side