I have the VM up and running OK on a workstation class machine. I know I need a server, but what specs (RAM, CPU, HD, etc)?
That depends very much on what products you plan to use, and how many nodes you'd like to manage.
A really rough rule of thumb: a workstation type system with 4 cores (virtual or logical cores), 8GB of RAM and 300GB of disk will easily handle hundreds to thousands of nodes, unless you are using opFlow. opFlow needs more resources, and fast (and plentiful) disk resources are required for it to scale well. The opFlow V2 (deprecated since v3) Installation Guide has more info regarding its storage requirements.