16:9 for a PC is just a massive waste of screen space for most things because 90% of apps and web pages are designed, if not with 4:3 in mind, then to support 4:3 and so you end up with horizontal letterboxing all the time.
True, they are not designed for 16:9, but most are designed with a ratio of equal or greater vertical to horizontal. i.e. you can stretch the vertical as much as you want and it'll still look good. So just rotate the monitor and use 9:16. I do this on a few of my monitors, esp. the ones that I use for editing for reading the web and it works out very well.
If you use X, xorg.conf section:
Section "Screen"
[snip]
Option "rotate" "ccw"
[snip]
EndSection
or your vid card manufacturer may have a custom app to rotate.