I'm votin' for the Mac Mini. It's what I use and although I do have a few rPi, and have installed Homebridge on them more than 5 times, the Mini is where it belongs for me.
Installation is simple and there are plentiful guides. You do NOT need Brew/HomeBrew or anything else, just click:
Latest LTS Version: 12.16.1 (includes npm 6.13.4)
and save the result, install normally.
You'll end up with Node and NPM installed.
Then use @dan.t guide to installing Homebridge and use his great tool for creating an excellent starting config.json