General Knoppix support for those who've read the FAQ at the Wiki
$198.00
HP ProLiant MicroServer Gen8 G8 G2020T 8GB RAM 4x 1TB HDD 4x 3.5" 712318-421
$249.99
HP Proliant MicroServer (Model: HSTNS-5151) NO HARD DRIVES-Power Tested,
$99.99
HP ProLiant MicroServer Gen8 | Intel XEON E3-1220L V2 | 8GB RAM | NO HDD | 4 BAY
$249.99
SuperMicro Server 505-2 Intel Atom 2.4GHz 8GB RAM SYS-5018A-FTN4 1U Rackmount
$202.49
Barracuda Supermicro CSE-825 720w PSU 2U 8 Bay Barebones
$169.95
HPE ProLiant MicroServer Gen10 Plus v2 Ultra Micro Tower Server - 1 x Intel Xeon
$846.48
1U Supermicro Server 10 Bay 2x Intel Xeon 3.3Ghz 8C 128GB RAM 480GB SSD 2x 10GBE
$273.00
Micron 16GB (2x8GB) 1RX8 PC4-2666V-RD1-11 ECC RAM 2666V MTA9ASF1G72PZ
$29.99
SUPERMICRO 1U Server 1028U-E1CRTP+ 64GB DDR4 | x2 Xeon E5-2640 | Avago MegaRaid
$229.00