http://www.arduino.cc/
These little arduino microcontrollers are cheap and easy to use, you can get add-on boards to drive higher current devices such as ignition coils. They only cost $30 or so.
You'd only need 2 digital inputs to sense the pulses coming in, and then 3 digital outputs to deliver the sparks, a little code and you'd be done. They are easy to program and they are all open source with lots of support and examples online etc.
:O)