In order to hold quality video conferences, you are going to need a smart camera. The AVer CAM520 Pro has you covered. It is a 1080p camera with auto framing based on facial recognition. It has 18x total zoom capability (12x optical). The CAM520 Pro also has RS232 integration.
The CAM520 Pro has auto focus and smooth pan, tilt, and zoom. You can find out more about it here.