Build your own ignition system?

Is there anyone out there who have built their own ignition systems? I have looked at AEM, http://www.aemelectronics.com/index.php?cPath=18_19/ But to make this work i need something to controll the sparkadvance for different manifold pressure and RPM by electronics, any ideas where they use such device?
I could just buy myself a proven good EI, but whats the fun in that?
And it is a small father and son contest, because in late 80`s my dad modified two Suzuki GSXR 750 ignition systems and used them on his RV-4 with great results. So it would be fun doing something similar....


Pic of the Suzuki systems coil set up

I built one with a PIC micro, an IGBT, hall-effect pickup, some resistors, caps, etc. on a breadboard, hooked it all up to my lathe, and was firing a GM coil pack. That's as far as I got. Its a subject I will definitely revisit in the future.

I built a megasquirt system on a VW rabbit race car once. Does that count?

The man to talk to would be Mark Landoll. Contact him and I guarantee you will know more than you did before you met him.

Built a dual ignition for a Suzuki conversion using ND pickups, GM modules, and (if I remember correctly) Toyota coils, a system pioneered on the old AirSoob list. Worked great.