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Mailinabox
https://www.serverrack24.com/10-inch-12u-server-rack-with-glass-door-312x310x618mm-wxdxh.html
I don't have USA links sorry but that's the general gist
10" racks
Consolidate power might not be possible 12v? Even 20amps is 4-6 computers. Just get 10" pdu's they have 3 plugs. I know there's 17 computers and 3 switches that's like 7 pdu's..
20 shelves
2x 10u 10" racks..
You'll need to have a 10u empty to keep going for expandability.
You got answered on r/mikrotik ?