Hardware recommendations for OPNsense upgrade (Suricata + Zenarmor, fanless, 6–8 ports, <$300)

I’m looking to upgrade my OPNsense firewall hardware and could use some recommendations from people running Suricata + Zenarmor on fanless systems.

Current hardware:

• Sophos XG 125 Rev.3 It’s been reliable, but once I enable Suricata or Zenarmor the CPU gets overwhelmed and throughput tanks. Time to move on.

Requirements for the upgrade:

• Must handle Suricata on WAN + Zenarmor on LAN without major performance loss
• Fanless only (noise is a hard requirement)
• 6–8 Ethernet ports (Intel NICs preferred)
• Budget: under $300
• Low power consumption is a plus