Yeah, I went with mini PCs myself. Have a Lenovo M720 Tiny and a Dell Optiplex 3080 Micro (they are virtually almost the same). You can change parts, there are ample ports available and you can pretty much run any OS you want. In the Dell you can even put 3 storage drives (1x 2.5" and 2x M2) so perfect for an SSD NAS.