It is my understanding that I can do the job with a Digital Camera.  How do I get the camera to output something into its USB port so that I can use the information?

Should I just buy a webcam?  If so… how do I go about removing the IR filter?

Who said you could use a digital camera?  You can use camcorders if they have a IR night mode.

The digital camera would have an IR filter built in, and wouldnt be suitable. Unless i’m missing something.

The easiest thing to do it is to get a web camera and buy a seperate lens assembly unscrew the old one and screw in the new one (some links are in the wiki), that way at the end of the project you can still use the webcam normally if you wish.