HI,
I have just had my new Cyberdata SIP Intercom delivered today and it works a treat (on the bench).
Setup to 3CX took minutes and it has some nice features such as POE compliant, built in relay for door strike that can be triggered using DTMF, upload audio files to customise rings an alerts.
Ordered it from VoIPSupply.com about a week ago. Link is http://www.cyberdata.net/products/voip/index.html
Troy.