The power supply can be as simple as a plug in transformer, such as the black enclosed ones or a doorbell transformer. The enclosed ones are the exact same thing, occasionally fused. Just be careful because most doorbell x-fmrs come in 12, 16, or 24v. If you need dc, just put a bridged rectifier inline on one of the secondary legs, and that will give you simulated dc, enough to run the camera. You could easily hard wire it into the vcr's power supply. As for as using a supply already installed in the vcr, I would tend to stay away from that. Seems like trying to put it in the vcr would be a large pain in the butt and there are many other options that would save you a lot of trouble. Do a search for spy shops and you'll get more than you'll want to even look at. Just buy the camera and make your own setup. Most of the prebuilt ones are way over prices.
As for as the wireless, there was a special on Dateline a month or two ago where a guy rode around in his truck, with a laptop and a home-made directional antenna, and picked up the X10's very easily. Food for thought.