You can get somewhat faster relatively affordably - there's also a tradeoff between speed and resolution, but if 640x480 will work, the [link|http://www.ptgrey.com/products/dx/index.asp|Pt Grey Dragonfly Express] for example, maxes out at 200 frames/sec at 640x480 (real speed may be slower; it's a 1394b Firewire camera, and they spec a certain image format). IIRC, that model is around $1000.

Be prepared to do some experimenting, especially with lighting and software. One cheap light source is high frequency flourescent lights (something like 400Hz flicker instead of 60Hz).

There are commercial, relatively "plug and play" solutions for web inspection (offset printing); but I haven't heard of anything for what you describe.

In my experience, machine vision has been both very cool and very frustrating. It is very easy to spend a lot of time trying to tweak the system for best results.

In fact, I have one final suggestion - see if you can setup the vision software to do regression software. I mean something like this:
- get the camera running and take a whole bunch of pictures (at least 100) that you're happy with (e.g. good image quality), and record what the vision system should give you back.
- then write a program that will feed the images to your vision software, and record the results compared to what the results should be
- and every time you tweak the machine vision software, run the test case, and check if the results are better or worse.

I did something similar with my Cognex camera (to make sure the results were good on a variety of pictures, not just the one I used to adjust things).

Good luck,
--Tony