Well, a 4k monitor has exactly 4x the pixels of 1080p. That means it is crystal clear at both 4k and 1080p with no interpolation. You would have the option of running 4k for some things and 1080p for demanding games. Of course that would be more expensive than a lower resolution monitor but 27" 1080p is an unusual format now. You'll have more luck finding 2K or 4K.

In 27" IPS gaming monitors I think you have 3 choices but they aren't 1080p
Swift PG279Q 2K 165Hz, G-SYNC
Swift PG27AQ 4K 60Hz, G-SYNC
ASUS MG279Q 2K 144Hz, FreeSync

The advantage of g-sync and freesync are that your monitor will only refresh as fast as your GPU can handle so you don't have to render 144 FPS or 165 FPS to eliminate tearing.

I also recommend buying from an online shop that allows returns when buying a monitor. If you happen to get a monitor with dead pixels or excessive edge glow then it's good to be able to exchange it. And as always I recommend reading further on any display you consider, both professional and owner reviews before buying.

I don't know why they would be bad at 1080p. The problem is when you pick a resolution in between, then the monitor has to interpolate and things get fuzzy. As long as the resolution is exactly half of native it should just use 4 square pixels to make one large square pixel. But you may be right if the monitor doesn't do that correctly.