My desktop computer is a NUC i5 running proxmox, and the Debian lxde GUI, it has a couple of FreePBI’s, a Kamailio proxy, a Plex media server , and even an XP VM for my USB connected weather station, all run fine within 16g of memory, I choose zfs while installing and created vm’s for ease of management and offsite backups. You have a changeable choice of network adapters to present to any VM, a 4x4 quiet multipurpose box on the wall , think of a ‘wallboard’ or FOP2 ‘kiosk’ attached to the HDMI port, all for probably less than 600 bucks.
Add another nuc and take advantage of the inbuilt HA cabablities to save on licensing