Look through here - http://forums.hybridz.org/index.php/forum/93-megasquirt/ for EDIS. Notice though, that you'll need an aftermarket EMS, like Megasquirt, to trigger it.
What might work better for you is a Pertronix unit, or a 280Z distributor with a separate GM HEI module, or a 280Zx distributor with a built-in E12-80 ignition module.