Baba Classes

I need a html/WebRTC based classroom which is first and foremost FAST, responsive, and SCALABLE and is iOS ready with an APP which can be used along side the web app. It needs to have the following: 1) Whiteboard with regular tools shapes , grids etc 2) Ability to SCREEN-SHARING (Google Hangout type), 3) Audio and video communication without LAG can be built on opentok or agora etc) , 4) Presentation (ability to upload powerpoint/pdf while having the ability to Highlight, write etc using the whiteboard tools, text chat, user permissions and 5) Database (Moodle for LMS) + CMS (content management system) SOURCE CODE are available and their integration is required. Also, i would like the classroom to hold WEBEX, while doing PPT presentation and 100s of people in the room watching.