If you feel like you have a headstart in Django, I'd go that route.
Else, I might be partial to do it in something like Rails that would allow me to write almost 0 lines of code, instead just spend time connecting various gems, libraries, etc and make a push to Heroku and get a proof of concept up.
While Proof-Of-Concept is running (free on Heroku) I would probably spend time rewriting it in Python or if you become partial to Ruby, just sticking with it...