General Knoppix support for those who've read the FAQ at the Wiki
DELL PowerEdge R730XD Server 2x E5-2697v4 2.3GHz =36 Cores 64GB H730 4xRJ45
$407.00
Dell Poweredge R630 2x Xeon E5-2680 v4 2.4ghz 28-Cores / 128gb / H330 / 2x 1TB
$334.99
Dell PowerEdge R630 Server 2x E5-2680 V3 =24 Cores | 128GB | H730 | 2x 600GB SAS
$464.99
DELL PowerEdge R730 Server 2x E5-2690v4 2.6GHz =28 Cores 32GB H730 4xRJ45
$333.00
Dell PowerEdge R730XD 28 Core Server 2X Xeon E5-2680 V4 H730 128GB RAM No HDD
$389.99
Cisco UCS C220 M3 1U 2x 6-Core Xeon E5-2620 2.0GHz / 64GB RAM / No HDD
$89.99
Dell PowerEdge R620 Server 2x E5-2660 v2 2.2GHz 20 Cores 256GB RAM 1x 480GB SSD
$139.99
Dell PowerEdge R630 Server 2x E5-2640v3 2.60Ghz 16-Core 64GB H330
$182.65
DELL PowerEdge R630 8SFF Server 2x E5-2680v3 2.5GHz =24 Cores 32GB H730 4xRJ45
$230.00
Dell PowerEdge R710 2.5" 2U Server 2x X5670 2.93GHZ 12-Core 128gb 2x 1TB SAS
$114.99