While there are hundreds of headset manufacturers. We highly recommend both Jabra and Plantronics Headsets. Jabra and Plantronics have a compatibility guide on their website which list 100 devices (wired and wireless) that are compatible with the Cisco phones. Jabra and Plantronics provide full support, setup and troubleshooting on all their products.
Below are links to their compatability tools.
• Select Office Phone
• Select Phone Vendor Cisco
• Select Phone Model (XXXX) supported Cisco IP Phone
For other headsets besides Jabra or Plantronics please check with your headset manufacturer for compatibility with the Cisco IP Phones.