We've got an [link|http://z.iwethey.org/forums/render/content/show?contentid=268433|Axis 207W]. We monitor a bedroom with it and its fine for that. The ability to pick out features is going to depend on the lighting, the sharpness of the lens, and the resolution of the sensor. The 207W has an auto-aperture feature to adjust the exposure, but I wouldn't call it a high-resolution system by any means.
Your best bet is probably to put up a couple of cheap cameras out in the open with lots of signs and realize that most hoodlums won't stop to consider that it won't really be able to capture enough detail to uniquely identify their faces. Coats, shirts, general sizes, etc., is probably enough for at least a circumstantial ID.
Based on the quality of bank video shown on TV, I don't think you'll get what you want for a reasonable price just yet.
HTH a bit. Good luck.
Cheers,
Scott.