General Knoppix support for those who've read the FAQ at the Wiki
HP ProLiant MicroServer Gen8 G8 G2020T 8GB RAM 4x 1TB HDD 4x 3.5" 712318-421
$279.99
Supermicro 1U Server X9SRI-F Xeon E5-2640 v2 2.5Ghz 16-Cores / 64GB / No HDD
$149.99
SuperMicro SuperServer 5038MR-H8TRF Blade w/X10SRD-F Board E5-2630v3 Proc 128GB
$263.96
Barracuda Supermicro CSE-825 X10DRH-CT 720w PSU 2U 8 Bay Dual E5-2620V4 32GB
$189.95
HP ProLiant MicroServer Gen8 Desktop Computer Intel Core i3-3240 8GB Ram
$224.99
HP Proliant HSTNS-5151 Microserver (618364-005) NO HARD DRIVES - WORKS
$149.99
HPE ProLiant MicroServer Gen10 Plus v2 Ultra Micro Tower Server - 1 x Intel Xeon
$846.48
DATTO-1000 Mini PC Micro Server 8GB RAM
$67.48
Dell PowerEdge R7425 2x AMD EPYC 7251 64GB RAM H730P RAID NO HDD/OS #73
$640.00
ArcServe UDP 8200 SuperMicro X10SRW-F 32GB RAM Intel Xeon E5-2620v4 No Drives#73
$240.00