I run Opnsense on a Proxmox VM (I followed this guide). I’m quite pleased with it. Opnsense is probably going to be more secure than any consumer router firmware, but you’re going to have to make a bigger upfront investment in hardware. I had never used Opnsense prior to using this system, and the fact that I’m running it on Proxmox is a huge benefit. If I’m ever about to do anything I’m unsure of, I can snapshot the VM in Proxmox. If my router config breaks as a result of my tinkering, I can easily restore from the snapshot.

I definitely don’t need the SATA ports. I have a vision of putting this board in a 1u chassis. I’m sure AliExpress also has a 1u version of this hardware…

Good tip. I’ve definitely looked at the Fujitsu boxes. However, I’m located in the US, and Fujitsu never sold those in the States, so they’re hard to find. The shipping fees from the EU seem to be in the $50-$90 range, which eliminates any cost savings.