Here is a link to a system on 6mmbr.
http://bulletin.accurateshooter.com/2011/12/diy-big-screen-target-cam-system-with-high-gain-antenna/
If you use the "search this forum" function in the top right corner of the Precision rifles forum and type in wireless camera you will get about 10 hits. The first couple list components CGNers have put together and are using.
All that is needed is a wireless IP camera and a Cambodian Tire power pack to get the juice and a notebook computer with wifi router, you can get a Trendnet wireless IP camera cheaper if you follow Dell's days of deals. A name brand camera with optical zoom in lieu of the useless digital zoom is the best but for some reason they are ridiculously expensive.
The bundled camera software is sufficient to record and more.
Do you know max distance for wifi?
Do you know max distance for wifi?