I’ve been running OPNsense as a VM in Proxmox for a year on an AliExpress box that doesn’t have ECC. If I might ask, why do you have a requirement for ECC?

Before this box, I ran a Dell R230 with pfSense but got tired of the noise and 40 watt power draw.

I’ve had zero issues without ECC, so I’m just curious about your need for it.

Zabbix for agent / snmp based statistics.

Uptime Kuma for up/down states with a webhook notification into Discord so I get instant alerts on my phone when one goes down.

I’m going to go a different route than your question. If you have a spare m.2 slot and room in your PC, you can install a m.2 network adapter. I recently installed a m.2 to 2.5gbe adapters in a Dell 3060 SFF as a proof of concept at home for getting Proxmox ceph cluster working over 2.5gbe.

I used this adapter. https://www.ebay.com/itm/256214788974?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=96RQC3CqQ_u&sssrc=4429486&ssuid=9BfwgvpgRMG&var=&widget_ver=artemis&media=COPY