Sounds like Oona Laurence from Southpaw could be a great option http://www.imdb.com/name/nm4802218/?ref_=nmbio_bio_nm apparently she is excellent in this movie.
Perhaps a tad young right now, but if they don;t start filming until late next year she will almost be the exact right age for Ellie. Recall in the game Joel thinks Ellie is 12, and Ellie snottily corrects him that she's 14 actually. So it's preferable, I think, for Ellie to look younger than her age, which would be impossible for any girl over the age of 16 to pull off.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix
