[eilyra]

They kind of are a thing, there's the LG 43UD79-B[1] which is a 43" UHD monitor. Not the biggest screen, but decently sized and it advertises a 5ms GTG response time which should be adquate for monitor like use.

[1] http://www.lg.com/us/monitors/lg-43UD79-B-4k-uhd-led-monitor

[pault]

Be careful to check of those things support HDPC or whatever it's called. I have the Dell 42.5 inch monitor and it won't play 4k content.