I have a setup for my glider which works well. In my case, the camera is powered by a 12V LiPo battery. I'm not at home, so can't look up the model number, but here is a link to something similar.
900MHz Mini Wireless Color Camera w/Built-in Microphone
Camera is powered by a 9V battery. Receiver would probably be powered by a UPS backup battery, also 12V. Because the receiver has RCA connectors, it can be hooked up to a portable TV or video camera.