I wouldn't be so keen on a 4K monitor. Comparing the dimensions of that to mine I think it would be too much looking up/down if you're that close.
32" 16:9 is pretty comparable to 34" UW. The former just being slightly taller and narrower in roughly equal amounts. I'd say it's down to personal preference and how you'd use the space.
Ah yes, I just looked at the dimensions and didn't realise it included the stand. Looks like a 32" 4K would be about 25% taller in the screen which I think I'd find too much but obviously each to their own.
I generally use the ultrawide as akin to two monitors.
32" 16:9 is pretty comparable to 34" UW. The former just being slightly taller and narrower in roughly equal amounts. I'd say it's down to personal preference and how you'd use the space.