I have one dedicated for opnsense, which runs my firewall/router. I used to use a Ubiquiti ER-Lite, but its compute power was a little lacking for certain features I wanted running. One of the niceties of running pfsense/opnsense on a “real” computer is that it just runs faster and boots faster after a software update, haha. I also have tailscale on it so that I can remotely access my home network.

Opnsense can technically be run as a VM on proxmox, but it’s generally not advised to do so. The proxmox machine is running unifi network for my ubiquiti wireless AP, adguard home, home assistant OS in a VM, and frigate in a VM, but I’ve been thinking of consolidating the various container services and VMs into just all containers running on a uCore OS installation instead of proxmox.

Wow, that’s a great deal. I currently have two: one w/ a dual 1-gbe NIC for opnsense and another for proxmox

A mini PC could certainly work! If you’re willing to go ebay, I’d recommend any of these Lenovo Thinkcentre SFF PCs:

https://forums.servethehome.com/index.php?threads/lenovo-thinkcentre-thinkstation-tiny-project-tinyminimicro-reference-thread.34925/

1-2x m.2 slots, 1x 2.5" slot, and some can accommodate a half-height PCI-E card in place of the 2.5" slot. Presumably, you’d want to go Intel for QSV