Ultrawides don't play as nice with OS workspace management and can't provide physical partitioning/prioritization (e.g. primary windows on main screen virtual desktops, auxiliary windows on secondary screen virtual desktops). They also tend to not measure up to regular monitors in terms of specs.
4k TVs put heavy constraints on desk arrangement to get satisfactory perceived sharpness and UI scale and come with all sorts of extraneous TV junk (unless you go with an ultra-basic or signage model, which are anemic in terms of panel capabilities).
My preferred setup would be 2x 16:10 30-32" monitor or a single 16:10 30-32" monitor accompanied by a 1:1 or 5:4 secondary monitor that's height-matched to the primary monitor, but that's not practical so I go with the pretty-standard setup of 2x 16:9 27" monitors. If I absolutely had to go with a TV-like setup though, I think it'd be with a BFGD (big format gaming display), because the panels on those are more monitor-like and they don't have all the cruft that TVs tend to come with.