Connect FreePBX to Mac Users

I am looking for someone who can help us with FreePBX VIOP located on our server. The system is in place and operational. We are using Gizmo5 for softphone for PC users (working fine), but now we have 2 new agent who use Mac we need someone who knows how give us instructions of how to connect the Mac users to our FreePBX VIOP which is on our own server. We need someone to take a look at all of the set up to make sure all is correct and do a security sweep of the server.