General Knoppix support for those who've read the FAQ at the Wiki
1U BareMetal pfsense opnsense Router Firewall DNS Server 6x 10GB Ethernet Ports
$149.00
1U 20" Short Depth Server Firewall PFSense X11SSH-F Xeon 3.5Ghz 32GB RAM NVME
$247.00
1U Supermicro Server 10 Bay 2x Intel Xeon 3.3Ghz 8C 128GB RAM 480GB SSD 2x 10GBE
$273.00
Supermicro 1U X11DPU 2x Xeon Gold 6132 2.6GHz / 128gb / 10x 2.5 Trays / 2x 750w
$649.99
Open Eye OE-MTX08 8TB Micro Server With Linux (Boots To Login) No Accessories
$282.92
HP ProLiant Xeon E3-1220L V2 MicroServer Gen8 2.30 GHz 16 GB RAM NO DRIVESorCads
$200.00
CEOhack 1U X9DRW-3TF+ 4 Bay Server 64GB DDR3 1x E5-2667 V2 3.30GHz 8C 1x 1TB HDD
$119.00
SUPERMICRO ELEMENTAL server 118-18 x2 500gb hdd
$129.99
UNRAID Supermicro 4U 36 Bay Storage Server Xeon 20 Core 3Ghz 256GB X540 10GBaseT
$588.00
Supermicro CSE 823-6 2U 6 Bay Chassis ,1xPWS 653-2H 650Wsold as in the photo,
$119.75