I apologize for my ignorence, but CCTV is not my expertise.  I am doing the low voltage installation on my new home and I want to pre-wire for color day/night video cameras.  I will be running RG6 to each installation, but I am unsure of what gauge wire I should run for electricity.  The runs will be a max of 125 feet.   
  
I will be using a modulator to see the cameras around the house.  Can I also hook to a old TIVO and small TV to record and put on loop? 
  
THANKS