General Knoppix support for those who've read the FAQ at the Wiki
Dell Precision 5820 XEON W-2102 2.9GHz 16GB 256GB (x3) Quadro P5000 Workstation
$272.79
INTEL XEON GOLD 6242 2.8 GHZ PROCESSOR | SRF8Y
$499.99
Dell Precision 5810 Workstation Xeon E5-1650 6C 3.5GHz 16GB 500GB Win10 K2200
$124.67
HP Z420 Workstation Xeon E5-2690 v2 3ghz 10-Cores 32gb 240gb SSD 1TB Win10
$189.99
Intel Xeon E5-2697 V4 2.30 GHz 18C 2011-3 2400MHz 45MB 145W SR2JV CPU Processor
$49.99
Intel Xeon Gold 6140 SR3AX 2.3GHz 18-Core Processor CPU
$39.99
Intel Xeon E5-2697A V4 2.6GHz CPU Processor 16-Core Socket LGA2011 SR2K1
$39.99
INTEL Xeon E5-2697 V4 SR2JV 2.30GHZ 18-Core CPU 2697v4 GRADE A CONDITION @ A
$49.99
SRF8T INTEL XEON GOLD 5218 2.30GHZ 16-CORE 22MB 125W CPU PROCESSOR
$297.00
HP Z820 Workstation 20-Core 2.50GHz E5-2670 v2 128GB No HDD No OS
$284.89