General Knoppix support for those who've read the FAQ at the Wiki
Dell PowerEdge R720 Server - 2x8c CPU,256Gb RAM, 128Gb SSD/3x900Gb SAS, Proxmox
$340.00
DELL PowerEdge R730 Server 2x E5-2690v3 2.6GHz =24 Cores 32GB H730 4xRJ45
$274.00
Dell PowerEdge R720XD Xeon E5-2680 V2 2.8GHz 20 Cores 256GB RAM 12x4TB
$510.00
Dell PowerEdge R730XD 28 Core Server 2X Xeon E5-2680 V4 H730 128GB RAM No HDD
$389.99
Dell PowerEdge R730, 2 sinks, SystemBoard, 8 trays,H330,Idrac 8 exp, 2x750w Psu
$135.00
Dell PowerEdge R620 Server 2x E5-2660 v1 2.2GHz 16 Cores 256GB RAM 2x 300GB HDD
$79.19
DELL PowerEdge R730 16SFF Server 2x E5-2690v4 =28 Cores No RAM/ HDD H730 4xRJ45
$232.97
Dell PowerEdge R630 Dual Intel Xeon E5-2603 v3 1.60GHz 64GB RAM No HDD H330
$174.50
DELL PowerEdge R730 Server 2x E5-2680v4 2.4GHz =28 Cores 32GB H730 4xRJ45
$284.00
Dell PowerEdge R420 2x Xeon E5 -2440 V2 1.90GHZ 128GB DDR3-1600MHZ 2x 550W PSU
$110.95