Its fairly easy to make a cable to run your ST/STacy/STE/Mega/etc to a regular PC VGA monitor and get _mono_ support (assuming you can find the right DIN connector for the ST side.) and hence there are numerous options on ebay etc over the years, or roll your own.
Is there any easy to get widget to get ST low/medium on a VGA monitor? (something direct; I'm betting ST -> composite -> VGA exists, but would suck
A TT030 or Falcon can go direct to VGA if memory serves, but for the ear