General Knoppix support for those who've read the FAQ at the Wiki
HP ProLiant DL380 Gen9 8SFF Server - E5-2698 v3 - 32Cores - 128GB Ram - 1TB HDD
$299.00
HP ProLiant ML350 Gen 9 Server 64GB RAM 2.4GHz Xeon 12-Core E5-2667 v3
$300.00
Dell Poweredge R630 2x Xeon E5-2680 v4 2.4ghz 28-Cores / 128gb / H330 / 2x 1TB
$279.99
Lenovo SR530 Server (Intel Xeon Silver 4110) (3x 800GB SSD) (NO OS) (48GB RAM)
$599.00
Dell PowerEdge R620 Server 2x E5-2660 v2 2.2GHz 20 Cores 256GB RAM 1x 480GB SSD
$139.99
$125.00
HP Proliant DL380 Generation 10 Rack Mountable. 6 x 1.2 tb drives.
$499.00
SuperMicro Server 505-2 Intel Atom 2.4GHz 8GB RAM SYS-5018A-FTN4 1U Rackmount
$202.49
Tested CISCO UCS C240 M5 SFF UCSC-C240-M5S V03 Barebone Unit No SSD/Ram/CPU
$299.99
Dell Desktop Quad Core i5 8400 500GB SSD + 2TB HDD 32GB RAM Window Server 2022
$301.73