I like the live body-cam idea! You would have to pick the right person which is very easy to do if you have any wait line monsters working the line. You could put on a bit of a show selecting the person and mounting the camera on them in front of everybody etc…
You might try X-10 wireless camera’s, I have not used them in several years but they use to work pretty good and are cheap. Not sure how directional the antennas are, that could be a problem if you have to aim them. I’ve seen movies of people using them on rockets and the movies looked good so I’m guessing you would not need stabilization.
Also any video camera can be night vision by adding an IR LED. For a face shot you would only need one LED which would light up the persons face plenty and cost less then a buck or two. If you need any help with the IR LED illuminator feel free to give me a shout, I’ve made a bunch of them in the past.
Here’s the X-10 site: