Most of the ones I see work at 2.4 Ghz, which can apparently cause interference with wireless internet and wireless phones. How bad is this interference? Does a multi-channel receiver work around this interference?

I`m just looking at the real cheap options, some of these say that the signal strength is about 100 metres in an open area. But what about through walls and in winding corridors? My receiver would be placed about 20 metres from the camera, but there would be a couple of brick walls or doors in the straight line or some winding corridors the long way around. How badly does this limit the reception?

Any specific models that you would recommend that are affordable and available in NZ? Of course I would wanna use it on my pc, so the cpu usage while recording is another aspect. Would I need a video capture card with hardware mpeg2 encoder in order to limit my cpu usage while recording?

Thanks guys for any input.