General Knoppix support for those who've read the FAQ at the Wiki
Dell Poweredge R730xd LFF 14-Bay 2U Server | Choose Your CPU & RAM Config
$477.99
2U 12 Bay SAS3 SuperMicro Server 6028U-TR4T+ W/ X10DRU-i+ Barebone 12 Caddy RAIL
$299.00
Dell Poweredge R420 3.5" 2x Xeon E5-2430 2.2ghz 12-Cores 24gb 2x 1TB 2x 550w
$169.99
Dell PowerEdge R620 Server 2x E5-2660 v2 2.2GHz 20 Cores 256GB RAM 1x 480GB SSD
$125.99
Dell PowerEdge R730XD 28 Core Server 2X Xeon E5-2680 V4 H730 128GB RAM No HDD
$389.99
Dell PowerEdge R620 Server - 256GB RAM, 2x8cCPU, 120Gb SSD/3x900Gb SAS, Proxmox
$320.00
SuperMicro Server 505-2 Intel Atom 2.4GHz 8GB RAM SYS-5018A-FTN4 1U Rackmount
$202.49
Dell PowerEdge T330 Tower Xeon E3-1240 v5 3.5GHz 2x 1TB SATA HDD H730 READ AD
$160.00
Dell PowerEdge R220 1U Xeon E3-1220 V3 CPU 4GB DDR3 RAM ECC No Drive/OS Server
$103.99
Dell Poweredge R630 2x Xeon E5-2660 v3 2.6ghz 20-Cores / 16gb / H730 / iDracEnt
$219.99