Hello Paul, I've just read the specs of your problem and I'd like to help you. I used to work with InfoViz ([login to view URL]) and D3 ([login to view URL]), both tools are impressive and both really good. I think InfoViz has very good compatibility in mobile and tablets, so I'd like to recommend to use that tool. The only issue is that InfoViz is a bit slow with big datasets, can you please send me the table for building the graph?
I have free time to work this weekend and the work should be finished by next Monday. Please, do not hesitate to contact me for any further question you may have.