PfSense/OpnSense Firewall Hardware
NewEgg has Protectli hardware $250ca, fanless, 4x Gig eth ports, 0 Ram, 0 HDD. USB Wifi is an option. May have a free m.2 socket onboard. https://www.newegg.ca/p/2DS-001U-00002?Description=2%20nics&cm_re=2_nics–9SIA6XD5UV1629–Product Pfsense does sell