I placed a low bid on an auction for 25 Elitedesk 800 G1s on a government auction and unexpectedly won (ultimately paying less than $20 per computer)

In the long run I plan on selling 15 or so of them to friends and family for cheap, and I'll probably have 4 with Proxmox, 3 for a lab cluster and 1 for the always-on home server and keep a few for spares and random desktops around the house where I could use one.

But while I have all 25 of them what crazy clustering software/configurations should I run? Any fun benchmarks I should know about that I could run for the lolz?

Edit to add:

Specs based on the auction listing and looking computer models:

• 4th gen i5s (probably i5-4560s or similar)
• 8GB of DDR3 RAM
• 256GB SSDs
• Windows 10 Pro (no mention of licenses, so that remains to be seen)
• Looks like 3 PCIe Slots (2 1x and 2 16x physically, presumably half-height)

Possible projects I plan on doing:

• Proxmox cluster
• Baremetal Kubernetes cluster
• Harvester HCI cluster (which has the benefit of also being a Rancher cluster)
• Automated Windows Image creation, deployment and testing
• Pentesting lab
• Multi-site enterprise network setup and maintenance
• Linpack benchmark then compare to previous TOP500 lists