you can also get all of them through Steam if you need an easy means to deal with this, they are around two dollars each. Sadly 1 & 2 are not listed compatible with Catalina (Mac OS)
GOG has them, too -- with Linux packaging for us Linux people.
I bought MoO Classic and MoO 2 on GOG.com a while ago. I just tried installing and playing them on macOS Catalina, and I can verify that they work. But the stand-alone installers aren't notarized, so you'll have to approve them manually, or use the GOG Galaxy app.