AFAIK, LG's 5K monitors are their UltraFine series which have very bad reviews from actual buyers.
Do LG make a 27” 5K? They used to, but I thought they’d discontinued it.
Another brand
Dell has a 24" 4k display. I have it. It's decent, but the anti reflection coating can be seen on white background as a moire pattern. I hate that, although nobody else that I've showed the monitor to can see it.