Kat, I think Max has raised some issues that you need to think about, and decide which way you want to go. Once you made the choice of whether to go covert or overt it will be much easier to help with the technicalities.

FWIW, my job sometimes takes me into places that are covered by CCTV, and I personally have no problem with knowing that the cameras are there and that I'm being filmed going about my work. The way I look at it though, is that overt cameras, are there as a deterrent, and everybody knows where they stand. Covert cameras, it seems to me, is where you wan't to catch somebody in an act, rather than act as a deterrent.