Issues relating to HDD Installs. Once you have installed Knoppix, it basicly becomes debian, so you should check out www.debian.org for information.
DELL PowerEdge R730XD Server 2x E5-2680v3 2.5GHz =24 Cores 32GB H730 4xRJ45
$271.00
Dell PowerEdge R730 2x E5-2699V3 2.3Ghz 36 Core 128GB RAM H730 X520-I350 2x750W
$329.99
DELL R630 SERVER 8 x 2.5'' 2X E5-2680V4 32GB RAM IDRAC ENT & NDC 2X 495W PSU
$174.95
Dell Poweredge R630 Server 2x E5-2620 V4 =16 Cores | S130 | 32GB RAM | 2x trays
$159.99
Dell PowerEdge R630 Server 2x E5-2640v3 2.60Ghz 16-Core 64GB H330
$182.65
Dell PowerEdge R710 2.5" 2U Server 2x X5670 2.93GHZ 12-Core 128gb 2x 1TB SAS
$114.99
Dell PowerEdge R730XD 28 Core Server 2X Xeon E5-2680 V4 H730 128GB RAM No HDD
$389.99
Dell PowerEdge R720xd 26HDD 300gb 2.5-inch E5-2697 X 2CPU 384RAM 7.2 Tb HDD 
$180.00
DELL PowerEdge R730 Server 2x E5-2680v4 2.4GHz 28 Cores 32GB H730 Choose Drives
$337.00
DELL PowerEdge R630 8SFF Server 2x E5-2690v4 2.6GHz =28 Cores 256GB H730 4xRJ45
$562.00