OP, If you dont have a proxmox vm template ready to go, here is a great starting place using cloudinit:
https://github.com/UntouchedWagons/Ubuntu-CloudInit-Docs
You can use this with the proxmox gui cloudinit config as well to add your ssh key to each vm/etc.
Their e-meters are relatively basic. They just slap $200 of components in a box and charge $5000 for them