General Knoppix support for those who've read the FAQ at the Wiki
1U Supermicro Server 10 Bay 2x Intel Xeon 3.3Ghz 8C 128GB RAM 480GB SSD 2x 10GBE
$273.00
Dell Poweredge R730xd LFF 14-Bay 2U Server | Choose Your CPU & RAM Config
$499.99
Colfax CX75432 4U Server 2x Xeon E5-2660 v3 NO RAM NO HDD NO GPU
$699.00
DELL PowerEdge R730 Server 2x E5-2640v4 2.4GHz =20 Cores 32GB H730 4xRJ45
$259.00
Dell PowerEdge R420 Dual Intel Xeon E5-2440 v2 @1.90GHz 32GB RAM No HDD H710
$74.50
Dell PowerEdge R620 Server - 256GB RAM, 2x8cCPU, 120Gb SSD/3x900Gb SAS, Proxmox
$320.00
Dell PowerEdge R620 Server 2x E5-2660 v2 2.2GHz 20 Cores 256GB RAM 1x 480GB SSD
$139.99
SuperMicro Server 505-2 Intel Atom 2.4GHz 8GB RAM SYS-5018A-FTN4 1U Rackmount
$202.49
DELL R630 Server 2x 2697Av4 2.6GHz =32 Cores 256GB H730 4x 800GB SSD 4xRJ45
$812.00
Dell PowerEdge R730XD Server | 2x E5-2680 V4 28 Cores 192GB H730 | Choose Drives
$1230.99