Right now it’s the raspberry pi shortage. I have everything but the pi. Might just buy one assembled. Any recommendations on which one to buy?
Discussion
IMHO it doesn't make much sense to build a node on raspberry pi. They became very expensive (~160 $).
Haven't you considered to user refurbished mini PCs like Dell Optiplex, Lenovo Thinkcentre, HP Elite desk?
Then install Ubuntu or Debian on it, you can use following guides:
https://m.youtube.com/playlist?list=PLCRbH-IWlcW2A_kpx2XwAMgT0rcZEZ2Cg