Unless you're dead set on OSX, you could look into one of Intel's NUC kits [1]. I find this one pretty intriguing [2] (other than the skull thing, but they prov

Unless you're dead set on OSX, you could look into one of Intel's NUC kits [1]. I find this one pretty intriguing [2] (other than the skull thing, but they provide a blank faceplate as well), but it does limit you to an M.2 form-factor SSD. They are a bit expensive for what you're getting, IMO, but they are at least upgradable in some aspects, and similar in form factor to the mac mini. 1. https://www.intel.com/content/www/us/en/products/boards-kits/nuc/kits.html https://www.intel.com/content/www/us/en/products/boards-kits... 2. https://www.intel.com/content/www/us/en/products/boards-kits/nuc/kits/nuc6i7kyk.html https://www.intel.com/content/www/us/en/products/boards-kits...