I'm currently running two 780 Ti in SLI. I can try to run some tests with any games if you guys want. My monitor, however, is Cinema 30" Apple display. I'm just trying to bide my time till a good gaming 4k monitor comes out and some reviews on Titan Black (if it is a viable replacement for a 780 Ti).
edit: I just realized the above doesn't really help you
. I am happy with my SLI setup, but there are times where I think I could be fine with a single card. The only thing I can help give advice on is that the more Vram you have the better you can handle higher resolutions with ease. I know lots of people are saying for 4K, 6GB is good, more would probably be even better.