I don't know about the photography, but the train ride from Florence is 2 to 2 1/2 hours depending on what kind of train you take.

This one will knock off your socks! You do have to book a time to enter. I don't know about the non-flash pictures, either. The web site is www.cappelladegliscrovegni.it I'm not a gallery lover, but the 15 minutes we were allowed flew by. While you wait your turn, a good video is shown, which gives you an understanding of the history of this chapel. Make sure to look at the centuries old wood work, as well as the frescoes. Oh, and the adjacent museum is awesome. I loved Padua, they are to be congratulated on the conservation of their treasures and cultures. How long will you be there?

Just a thought. If the Chapel website does not answer your question, try the Tourist office www.turismopadova.it