I don't comment on 4k monitors to put them in good light. I'm 100% against that garbage marketing.
They're 99% of the times, selling consumers a monitor which they won't take advantage of. As soon as you touch the DPI slider, you throw away money, keep that in mind. I'm not the guy to ask for 4k monitor advice, and I apologize for that.
I will accurately answer any questions you might have about monitors though!
All the best!