You will not be happy running server on someone's workstation. First Filemaker Server 12 is dog slow compared to previous versions and adding the overhead of someone using the computer while serving files (especially with containers) could bring your work flow to it's knees. You would probably save money purchasing a used i5/i7 computer and having it do only one thing. Best bet is to have a separate computer, install only server on it, use 64bit Windows 7, turn off all windows effects, turn off file sharing and get 6 gigs of memory.
Thanks dbail and group, this was my recommendation also but we wanted to get a confirmation.
Your attention much appreciated!