Autospeed may have come up with a solution for our DC to DC converter problems. They used a laptop voltage converter rated at 80W (and tell how to increase that) to power a few simple things. Enough for the ignition and fuel pump? Perhaps, but at the price, you could probably just use two.
AutoSpeed - Voltage Booster
Here is an example I found on ebay.
http://cgi.ebay.com/UNIVERSAL-DC-CAR...d=p3286.c0.m14