There's quite a few, reasonably priced options for 4K screens at 27".
I've got an LG 34" Ultrawide which works great with my M1 MBP, but my M1 Mini can't drive it at the higher resolutions. You also need to check the resolution of the ultra wide if that's the way you go as a lot of them aren't 5K so you don't get a "retina like" resolution.
I'm in two minds about the ultrawide - I really like it but like
@russell_314 says, I have a similar issue depending what sort of work I'm doing where I'll have two windows side by side but think I'd be more focused with dual monitors. It's a strange thing to try and describe.