Hi Pete,
So did you ever find out more? We've been borrowing one from Lincoln University, its from Sextant Technologies. It is a Taupe wireless burrowscope that runs on batteries. It has a 2m hose on it and runs at a distance of 3m from the screen. The screen is very clear, the only improvement I would make is the screen is very small, 5x4cm, so would like a bigger version. Not sure what the total cost was.