Language Learning Program Website

Building a website for a foreign language learning program. Need a back-end coder to make a media player, custom content management system, securely link billing and subscription info, and mobile integration of website. For now, focussing on the functionality of one language, English > Spanish. But website and system will need to be expandable for multiple languages. Some specifics on the media player : Audio/Video lessons will be provided in chapter format. But, want to create a interactive multiple choice quiz at end of each chapter. Need buttons for user to toggle on/off subtitle text in the target language and its translation during lesson. Also, need buttons on player for slower playback and looping capabilities. When user logs out of the site, his or her place is bookmarked. And, can pick up right where he left off upon logging back in. For all intensive purposes, we want to emulate the structure of a another website called: [login to view URL] .