Depending on how handy you are the Ford EDIS4 setup is pretty good with a mega-jolt, then you have a completely self tunable spark setup and probably comparable cost to a custom dizzy.

I've just got my EDIS8 working with custom 36-1 trigger wheel fitted in the dizzy housing. This gives me 1 coil per plug and sequential fire but was a fair bit more pissing around. The Tech Wiki has all you need to know to do the EDIS4 conversion.