Start9 runs great on an old 2012 i5 Mac Mini. I bought their Pi4-based server initially and it still runs great but is not recommended for Bitcoin Core anymore (I run Vaultwarden and a SimpleX chat server on it primarily, now). I downloaded the OS for FREE and flashed it onto the Mini. They don’t *officially support DIY installs, but in my experience I receive just as much support from their amazing staff as I did with my Pi4. In fact, they only even ever ask about my hardware when it’s relevant (very rarely).