General Knoppix support for those who've read the FAQ at the Wiki
DELL PowerEdge R730 Server 2x E5-2680v4 2.4GHz =28 Cores 32GB H730 4xRJ45
$284.00
Dell PowerEdge R620 Server 2x E5-2660 v1 2.2GHz 16 Cores 256GB RAM 2x 300GB HDD
$89.99
Dell R630 Server 2x E5-2620 V4 2.1GHz =16 Cores 128GB DDR4 1x 960GB 2x 1G 2x 10G
$210.00
Dell PowerEdge R730XD 28 Core Server 2X Xeon E5-2680 V4 H730 128GB RAM No HDD
$389.99
Dell PowerEdge R720 Server - 2x8c CPUs, 256Gb RAM, 128Gb SSD/3x900Gb SAS Proxmox
$340.00
Dell Poweredge R720 8x 2.5" Bay Xeon E5-2650 2.8GHz 8 Cores / 64gb No HDD
$114.97
Dell PowerEdge R620 Server - 128GB RAM, 2x8c CPU, 128Gb SSD/3x900Gb SAS, Proxmox
$260.00
Dell PowerEdge R730, 2 sinks, SystemBoard, 8 trays,H330,Idrac 8 exp, 2x750w Psu
$135.00
DELL PowerEdge R630 8SFF Server 2x E5-2680v4 2.4GHz =28 Cores 128GB H730 4xRJ45
$384.00
Dell R730xd 26 Port SFF 2x E5-2697v4 36-Cores H730 128GB Server 2x SFP 10G ENT
$490.00