which tools or best framework for this idea ??

I am a web designer and a php coder ! My programming experience and knowledge started with My C++ courses at university more than 15 yrs ago. I have a question or a concern and I need advice.
I wanted to develop some kind of chat room, online, web based chat room, but this chat room would be a chat room where a soccer coach could invite his players to prepare a game or a practice session, in order to go over certain tactics, player or ball movements, and/ or drills, etc. ( you get the idea ! ) while off course - inter communication can also be done among the parties, questions, explanations etc... just like a normal chat room but with visual and animated elements that can be access and controlled by the coach . I was wondering, what tool ( or framework) or programming language would be best suited for such an application ? an application that could be a plugin to be installed and that could be accessed within a custom social network for example .. ?? any clues or direction would be very appreciated !!! ... thank you.

PS. I used Netbeans and Yii Framework for the online web app ( a social network )... How would I go about creating this special chat room that we should probably name it .. or call it : " an online soccer tactic & drill room ".