I would venture to say the majority of users run on a Pi. They can be perfectly stable, especially if you go through steps like running off of an external drive. This will probably be the cheapest route.
Next cheapest would probably be finding a used machine somewhere. It doesn’t have to be powerful or have much space. I myself run on an old laptop with a busted screen.
Compatibility with hardware isn’t really a concern. I know of none that only work when OH is running on one type of OS or another. Either OH supports it with an add-on or it doesn’t, whether it is running on Windows, Ubuntu, OSX, or FreeBSD.
Most people run on Debian based Linux distros which is the only OS which OH “installs” to, which is highly recommended if you have a choice.