HI Swiss
kelvin lights are superior to overdrive in my experience. We fit lights for our 24 hour race, six hours of which is run in the dark using the headlights and some street lamps.
We also have a guy called `Gary the Gadget`who buys the parts and fits light systems into your car. His system is as per KL but because we use variable voltage he fits a larger resistor to car so they will not burn out. If we can help mate I`ll let you know his number etc.