12V illumination is not much different than 110V. Halogen bulbs can give more light when compared to classic hot filament bulbs. It might be better to use 12V halogen bulbs for better illumination.
I do not like LEDS. They might produce good candle power per watts consumed, but I do not agree to the candle power measurements. Although the electronic machinery states the same candle power, I cannot feel the same light as compared to hot filament lights.