A simple idea to get independent high quality video for online interviews would be to cheat a little. This would only work if your not required to publish the video in real time.
The idea is to use dual recordings with the devices. For example. If the person to be interviewed has a high quality web cam but poor internet connection. The software could store a high quality video recording of his part of the session. In real-time the interview would be of the quality the connection can handle but because the stored part can be re-transmitted after the interview is done. It can then with the other videos restore the quality.