17-40 is a waste on a crop. And the Canon 10-22 outperforms the Tokina and they're almost the same price I think; not to mention the longer focal length.
Also the sigma 10-20 is worth looking into, nice wide angle.
Personally I'd get a Samyang 14mm for 380$. MF only, but that doesn't matter as you're shooting video. Also the IQ is 10x better than any lens mentioned in this thread.