I had thought about this for a while and finally found the parts to do it. The Sophos side is easy OS drive and DVD in the ODD bay and a dual or quad NIC on the motherboard. To pass the four drive bays to another server I needed to find a SFF-8087 to SFF-8088 converter:
For the Sophos NIC I am using an HP NC364T.
Disconnect the mini SAS connector from the motherboard and connect i