Have you tried security oriented distro Operator.iso by ussysadmin.org? It is based on knoppix and debian. Also it is one of the best network testing and pen testers tool?
Cisco ASA5525-FTD-K9 Security Appliance with FirePower Services
$1000.00
Dell SonicWall TZ400 Firewall Appliance
$39.99
Fortinet FortiGate 60F | 10 Gbps Firewall Security Throughput (FG-60F)- Open Box
$381.99
Ubiquiti Networks USG Unifi Security Gateway Router/Firewall
$29.95
Check Point Software Technologies L-72 Firewall & Security Appliance, w/ adapter
$69.99
Dell SonicWALL TZ300 | Firewall Security Appliance
$24.99
NetGate SG-2440 with pfSense Plus Console GNU Router Firewall Security Appliance
$69.99
Fortinet Fortiwifi 60D FG-60D Security Appliance Firewall / VPN w/ AC Adapter
$34.97
Cisco ASA 5506-X Network Security Firewall Appliance w/ Power Adapter
$79.99
Sophos SG-115 Rev 2 UTM Firewall Security Appliance 4-Port w/Power Adapter
$65.00