Spitfire makes a Predictive Dialer that can integrate with the IPitomy PBX.
The Spitfire server runs on a PC and registers to the PBX as a SIP Extension. Users will login their Spitfire Agent via client software, this sends a call to their extension (static or dynamic) and they will sit connected while the dialer makes calls. When someone answers and says hello, a tone will play to let the agent know they have a live call. When finished with the call, the agent will use the client software to hang up so their extension remains connected. If the agent hangs up the call, it will log the agent out.