I've been playing with a similar idea for a few years, not for airsoft but for restricted space reconnaissance. What I have is one of those tiny wireless security cameras, a portable power pack to run the receiver, and a head-mounted display. The theory is that one gets a vehicle's eye view of life... the idea works, but I was having some trouble with the interface between the HMD and the receiver. It seems that the brand of HMD that I have is somewhat particular about it's video signal. The result was that the image tended to drop out when the vehicle got more than ten feet away from the reciever. (Tests with a standard monitor revealed that it was not an issue with the signal strength from the camera, as the monitor gave a good image out to at least 40 ft: not sure I tested it further than that.) I have a few fixes in mind, but haven't got back to the project to test them. In any case, there are more HMD's available now than there were a few years ago: perhaps the new ones aren't as picky.
On an aligned topic: does anyone know where one can buy bulk tread (or even replacement treads) for a tracked vehicle?