How are you going to advance the timing?
If you are going to use a distributor, then it is a waste to use three coils.
It would be easier to use one sensor, and a PIC or ATMEGA to fire the coils, and to add the correct advance for the RPM and throttle opening.
You could also get a used ECU from the scrap yard, and the coils and sensors, all from a similar engine, and maybe even have that re-programmed to precisely match your engine and driving needs.
You could also look at Megasquirt, you can use it just for ignition or complete management, often available on fleabay for an OK price.
It may well be simple to make the engine run, but to make it rum properly is not going to be a 5 minute job.