i7 4790k, gtx 1070. I mostly play games like the witcher 3, Arma and flight sims like P3D and DCS i was thinking of the Dell 144hz 1440p monitor. Yes its not 4k but its 144hz witch is something i was looking into getting.
https://www.dell.com/en-ca/shop/dell-27-gaming-monitor-s2716dg/apd/210-agjr/monitors-monitor-accessories