1 TO 1 chat built with mongodb, nodejs and socket.io with express

Option A: A chat built with mongodb, nodejs and [login to view URL] with express to be integrated to our students forum written in php. we already had a chat that allows users to share text and photos as can be showned in the screenshot attached. so we need to add features to it like mongodb, sound alert, new message alert, typing alert, message sent alert, online/offline presence, load more users button etc. or Option B: we can build an entirely new app if the freelancer cannot work with other peoples code. i will like the session to be passed via php mysql session as well as local storage. the chat design interface will be disclosed to the selected freelancer. CRITERIA FOR BIDDING. 1.) you must provide a working demo of Nodejs chat working on mongodb you have already designed and must also have experience in design, php sessions and html5 local storage. Am a student so do not Bidd price that is impossible to negociate. Thanks