I have been pouring over the electrical thread and getting tons of ideas for my new little guy 6 wide. Here is the image courtesy of Joanne's electrical thread (Thanks very much!!!)

I would post the image directly but I have not quite figured that out yet (sorry).
I think I can follow this map to the point where I can replicate this setup but I have the following questions
1) Can someone take a guess at what this would cost in materials? I have good deep cycle batteries so that would not be an additional expense. I would also like to add in inexpensive stereo/DVD flip down/speakers to the setup.
2) Where would you suggest sourcing most of this stuff? HD/Lowes? RV Store? Ebay?
Really appreciate everyones help and support
Thanks
bg