Online Interactive Tutoring portal

We need a multilingual website developed that connects students and tutors through a social network style site, more or less similar to freelancer model, a crowdsourcing online tutoring system. The site must enable tutors to upload profile pages (including details such as name, age, subjects, syllabuses, experience, price, availability) that are then reviewed, interviewed and approved by the tutoring team and then searchable across all criteria. Students should then be able to request appointments directly with tutors based upon their availability as displayed in their calendars in their profile pages. Once an appointment is scheduled between a tutor and student they are supplied with usernames and passwords to sign into an 'interactive class'. A pricing model will also be incorporated. This needs to occur through an interactive whiteboard (software still to be decided upon but one of Scribblar, ScribLink, or Blackboard) that is fully integrated into the site. The site must also allow for payments to be made by student to the company accounts, that will then be transferred onto tutors as payment for classes but based on the feedback given by students. Open to suggestions on open source software in order to keep costs down. Important things to note are capability for building a multilingual site, it should automatically reflect the users region and open the home page accordingly, should have a comphrehensive database management system, automated scheduler, complete admin access etc