(SP4) What 4K External Monitor To Buy without Scaling Issues?

As the title says, I want to buy an external 4K monitor for use with my SP4. I'm currently using a Samsung PX2370 (1080 only) with the Surface brick dock and the scaling drives me mad when working everyday with large worksheets and moving windows around.

I've tried searching this sub but haven't come across a thread that specifically details which monitor to buy or at the very least, what size to get so that I dont run into scaling issues.

Ideally both SP4 and monitor will be at 200% scaling. I run my SP4 directly in front of my monitor, if that helps.