12v lighting is a waste of time in anything bigger than a 10x. 10 tool shed.
If your wiring a small remote cabin/ trailer, invest in a small ac inverter. You can get a hefty light duty modified sine wave unit pretty cheap. This way you can wire everything to standard ac code which anyone at homedepot can help with.
Most electricians I've met do not know how to handle dc well in terms of proper wiring and circuit protction. Forget weld, I've seen batteries melt box wrenches. 10,000s amps of short circuit potential in good deep cycle batteris!
Led bulbs re not magic, and they are not the most efficient, actually, compact fluorescent is th best deal going. The main Appeal for led is life and lack of hazardous metal, not efficiency. Curret led bulbs cost >>10x anything comparable and run 10% less efficient than the best. cFL. Why do you think they need to build led bulbs into huge heats sinks.
If you wire for ac, your options are much broader all around, and you can always back up using a genset directly.
People believe if solar, you are automatically limited to 12vdc, on the contrary, 12v dc is impractical above about 200w. Wire solar for 24 or 48v and use an inverter.