General Knoppix support for those who've read the FAQ at the Wiki
HP ProLiant DL380 Gen9 8SFF Server - E5-2698 v3 - 32Cores - 128GB Ram - 1TB HDD
$299.00
HP ProLiant DL360 G9 Server 2x Xeon E5-2690 V3 24 Cores P440ar 128GB DDR4 1x SSD
$279.99
Supermicro 4U 12Gbs SAS3 36 Bay E-ATX Storage Chassis w/Rear 2x 2.5 Rev B Rails
$499.00
HP ProLiant DL380 Gen9 16SFF 2x E5-2667v3 3.2GHz =16 Cores 32GB P840 4xRJ45
$280.00
Dell PowerEdge R720 Dual Intel Xeon E5-2643 @3.30GHz 128GB RAM No HDD H710P
$124.50
Dell R630 Server 2x E5-2620 V4 2.1GHz =16 Cores 128GB DDR4 1x 960GB 2x 1G 2x 10G
$240.00
Dell PowerEdge R730XD 28 Core Server 2X Xeon E5-2680 V4 H730 32GB RAM No HDD
$289.99
Dell PowerEdge R330 Xeon E3-1220 v5 3.0GHz 32gb H330 2x 3.5" Trays SVR 2012
$189.99
Dell Poweredge R730xd 2.5" 2x E5-2680 v4 2.4ghz 28-Cores / 256gb / H730 / iDrac
$519.99
DELL R630 Server 2x E5-2660v3 2.6GHz =20 Cores 64GB H730 4x 1.2TB SAS 4xRJ45
$361.00