I have an LG 21:9 but I don't know what the difference is between all those even after looking them up. I see a few minor variances but I don't know how to recommend one over the other.
For the price of the 29EA73 you might as well get a 34UM65, and if you went that far you might as well shake the cushions for change and see if you can get a 34UM95 out of it. But that's probably going overboard, yeah?
If it were me, I'd probably get the 29UM65 or spring for the 34UM65. I don't see any useful differences between 29UM65 and any of the other 29" models to justify the price increase. Certainly as you come closer to $500 I'd rather have the extra screen size than whatever the 29EA73-P has.