Monitor for Mac Mini M4

If you're willing to buy the speakers, webcam, and microphone separately, there are a lot of 27" 4K monitors with IPS panels and near-100% coverage of sRGB for under $1,000. They vary in whether they have features such as USB-C input, near-100% coverage of wide gamut (DCI-P3 or Adobe RGB), advanced color management, etc.

Some have thin bezels that would make it hard to mount a Webcam on top without obscuring part of the screen. The one I got has that issue.

27" 5K monitors are harder to find. I know of only three: the Apple, LG, and Samsung ones. The Apple one starts at $1600 and I doubt if you'd find it for much less. If I remember correctly, the Samsung one lists for $1600, but I've seen it for $800. The LG one lists for $1300, but I've seen it for $850.

There are too many to list. I'd suggest that you use Google to search and then narrow down using items like resolution, screen type, screen size etc....