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
HP T730 THIN CLIENT 8GB RAM 128GB SSD 4 port Gbe NIC GREAT FOR Firewall pfSense
$120.00
NetGate SG-2440 with pfSense Plus Console GNU Router Firewall Security Appliance
$69.99
Ubiquiti Networks USG Unifi Security Gateway Router/Firewall
$29.95
Fortinet Fortiwifi 60D FWF-60D Security Appliance Firewall Wifi VPN
$29.99
OPNsense six-port Gigabit router/firewall on Lanner FW-7535 hardware
$69.00
Fortinet Fortiwifi 60D FG-60D Security Appliance Firewall / VPN w/ AC Adapter
$34.97
Sophos SG 115W Rev 3 with Power Adapter - Firewall Security Appliance
$65.00
Palo Alto PA-4020 24-Port Firewall Security Appliance w/ 2x PSU
$182.11
Sophos SG-115 Rev 2 UTM Firewall Security Appliance 4-Port w/Power Adapter
$65.00