Im running several Nodes on a N100-System with 32GB RAM (32gb is possible).
Connected 11 external Drives per USB.
Works like a Charme, Never more than 21watts (System only).
Has the Power to run a win10-vm on top, but than the System is under Full load 
Take a Look at the N100 Mini-PCs.
I paid 180€ for the System and an additional NIC.