Fyi, though my answer includes hardware, the simplest solution ive found is to use a Jpac.
I've used GertVGA....shrug... its fine... but was missing a piece when I ordered it, so it took a long time to get it going. I've tried a few converters (but they were garbage... didn't save settings on restart, stopped working, etc). At some point I had custom firmware that let me output 15hz via composite (before that was officially possible) directly to an arcade monitor, but for some reason I didn't like that solution either. One day I plugged in my jpac and it worked fine. One and done.
Jpac is a known quantity, easily available and has other value as well. Unless price is the absolute determining factor, I'd consider it the obvious option.