Replying to 50mm for crop sensor dslr

Looking or a fast prime around 30mm focal length.

Anyone got any suggestions? im using a 7d/t2i

Rokinon 35mm f/1.4

Sigma 30mm f/1.4

and I think canon makes one around 28mm?

Has anyone done any tests with these? Which is better for video?

I've hear good things about the old pentax 50mm, is there an old lens at 30mm?