I went for the 10-22. I spent a long time deciding.
At the end of the day I had my choice list in this order
Canon 10-22 f3.5-f4.5
Tokina 11-16 f2.8
Sigma 10-20 f4-f56
Sigma 10-20 f3.5
Any reason why those two specific lenses?
I often post these links, these helped me in my decision although there may be other resources worth reading.