If this is really a 12vdc system and you are not connecting to the utility I doubt the electrical inspector will really care one way or the other.
I have thought of a bootleg 12v system myself, just as an experimening platform. There are lots of items from the auto and RV market that will work.
Just be careful once you get into the house, 12v will still start a fire. Other than that it is fairly safe. Once you start inverting it to 120 you will be entering the danger zone.
