Integrating FaceTime functionality into iPad app

My company is planning develop an iPad app that will rely heavily on video calls and I am trying to decide which API/tools to use.

Our requirements are as follows:

• High quality video with minimal delay or dropping of calls (provided users on each end have good connection)
• Good security
• Customizable UI; ability to move/resize video windows
• Ability to switch between FaceTime and iSight cameras; user would typically use FaceTime but could turn iPad around to use iSight when better resolution is required

I am well aware that there is no FaceTime API. Is there some other WebRTC-like API/SDK I could use that meets these requirements? Based on my research so far, OpenTok (TokBox) seems like the best bet.

AddLive is another API, though at this point, it seems incomplete. It is missing files from iOS SDK at least as of today.