As far as I know, any manufacturer making a current lens for Canon mount will AF on Canon bodies. Canon doesn't have the distinction between certain lower end models not being able to AF with certain lenses like Nikon does...Nikon mount lenses must specify whether they are compatible with the lower end Nikon models without focus motors.
As for UWA lenses, the Tokina 11-16 is usually the best reviewed of that bunch. I've been very happy with the Tamron 10-24, which is the next fastest, along with the much more expensive Sigma 10-20 F3.5. The Tokina 12-24 I don't have much knowledge of.
Sony DSLR-A580 / Sony 18-250mm / Minolta 50mm F1.7 / Sigma 30mm F1.4 / Tamron 10-24mm / Tamron 200-500mm / Tamron 90mm F2.8 macro / Minolta 300mm F4 APO
Sony NEX5N / 18-55mm F3.5-5.6 / 55-210mm F4-6.3 / Pentax K adapter / Konica K/AR adapter / bunches o' Konica & Pentax lenses!