Via another reddit thread on the topic, I found this YouTube playlist which has been super helpful. Just re-posting it here for posterity:
https://www.youtube.com/playlist?list=PLbNp7AIu8VYyzsocLUdCScF4zvou8rzS9
Thanks, y'all.
I don't think I need so many drives so now its just a matter of verifying that if I scoop one or two low-RAM-specs off of eBay for cheap I will be able to re-populate them with RAM.
Thank you for all of this info. I'm planning to slowly roll out three of these servers with Proxmox as a cluster. I'm just upgrading all of the available power outlets and spec'ing UPSes now.