Acer's Predator X27 display combines G-Sync HDR, a 4K resolution, and a 144Hz rate to make what in theory will be one of the best gaming displays on the market, though it probably won't be cheap.
http://www.notebookcheck.net/Acer-introduces-its-flagship-gaming-display-the-Predator-X27-monitor.214850.0.html