Two Outstanding All-in-One Linux Servers
The answer to this question depends on what you need. Zentyal is an amazing server that does a great job running your SMB network. If you need a bit more, such as groupware, your best bet is to go with ClearOS. If you don’t need groupware, either server will do an outstanding job.
I highly recommend installing both of these all-in-one servers to see which will best serve your small company needs.