Over time I have used several DC-DC converters and the TDC-320-12JG is by far the best. Its is not the cheapest but is very high quality and has a reputation for reliability.
I have a Degree in Electrical Engineering from the University of Technology Sydney and am employed in Broadcast Television Industry. My hobby is the (continuing) modification of MR02EV. I am also the National Treasurer of the Australian Electric Vehicle Association.