4k does give a better image but is more demanding. It's opinionated but if you are going with 4k, you might as well have a 27" screen or bigger. Again my opinion, but widescreen is much better for gaming and video editing than 4k. A wider screen enables you to see more real-estate, then a 4k screen.
The widescreen is also Gsync and IPS. Both great for what you need.