CTI for MAC OS for SIP_Phones - Simple One

We need a simple CTI-Client which communicates with the phone directly, communication with the pbx is not needed. We need this features/functionality: - call handling (answer,end,hold,transfer) - dialing from MAC OS adressbook - dialing from mac os filemaker-database (command development is sufficent gui/mask/field in database will be created by us) - namelookup from interal/central/phonebook and mac os adressbook(xml-format; template is available) More features like callerlist(missed,lastdialed,answered) are welcome but not mandatory. No preferred scriptlanguages. Sourcecode must be delivered to us and must bechangeable by us.