Thanks for your input guys
Ok, done a little more research today and it appears the cameras are infact twined cable with BNC and power.
I've got 2 options in powering these, first is wire them all up to a single purpose built camera power box.
Or secondly, plug them in individually to mains socket.
TBH, preferring the second option. The box sounds good but if it were to fail I'll be left vulnerable until a replacement is sourced/fitted.
Also, I think I could use Multiple output DC leads to save on sockets.
Regarding the monitor - The DVR is equipped with VGA and Coax.
So I'm pretty flexible on what screen to use.
Having said that I need 3!
Been quoted £249 for a 24' dedicated CCTV monitor - which I'd use for the main shop floor screen. I'll grab what ever bargains I can find for the other 2 -back office and top flat
Thanks