34 – 35″ UltraWide or ~32″ 16:9 monitor

You can’t run a 21:9 monitor at 16:9 resolutions like that without either significant distortion (stretching horizontally) or black bars at the sides. If you aren’t going to be using it at 3440 x 1440 much then there’s little point in getting such a monitor. You can certainly use it at lower than native resolutions, but you need to deal with the negative implications – this is explored in our reviews of UltraWide models in the ‘interpolation and upscaling’ section. And your reasons for not running the monitor at 3440 x 1440 would surely rule out a 3840 x 2160 monitor as well, for the same reasons?

The PS4 is restricted to 1920 x 1080, so that resolution would make most sense. If you feel your PC can cope with 2560 x 1440 but not higher, perhaps it would make sense to consider something like the AOC Q3279VWFD8 instead? I’d also recommend having a read through that review for some thoughts on Low Blue Light (LBL) settings on the monitor, or our other reviews. Even if not explicitly advertised there’s always a way to achieve an LBL effect. It certainly makes sense to reduce blue light exposure in the hours leading up towards bed time and some users like to use such settings for viewing comfort reasons at other times.