I would suggest a 27" – 32" monitor that has
- An IPS panel
- 100% or near-100% coverage of sRGB (basic color accuracy)
- Optional: 100% or near-100% coverage of wide gamuts (DCI-P3 and/or Adobe RGB)
- Modern inputs (DisplayPort, HDMI, USB-C (DisplayPort)) – preferably two or more, of mixed kinds. Note that a USB-C connection can carry video to a monitor and charging power to a computer over a single cable – which might be useful if you were getting a MacBook Pro, and did not have a separate dock.
27" 5K (5120x2880) pixel monitors are fairly expensive (especially the 27" Apple Studio Display).
27" 4K (3840x2160) pixel monitors are not as sharp, but you'll find many more of them, and a much wider range of prices. Some decent (if basic) ones are only $300 - $400 USD, compared to $1599+ USD for the 27" Apple Studio Display.