Oh, wow, musicalfan, it's gorgeous!
It really looks like Sam Barks, too, and I think you got the arms especially really perfectly.
And, as to a background...I'm not sure, but you did base it off the movie, so maybe something dark, kind of like the streets? And if you think you could, you could always add rain in the background, that would be pretty cool, I think. But really, it looks very, very nice already.