Darin is right in saying that the ignition control is probably more complicated than the fuel control.

On my system, I used the stock 22RTE distributor. It interfaces with a MSD 6A, which in turn interfaces with the FAST unit. I use one of MSD's tach adapters (I believe the one based on voltage) to drive the stock tach. The wiring was simple and the ability to use the stock distributor was actually one of the things that attracted me to the FAST, as at the time MS did not have spark control and the SDS system and Electromotive TEC II required fabricating a Hall effect sensor, which looked like a serious PITA.

Crank trigger ignitions are wonderful and very accurate, but most aftermarket setups and custom setups aren't well suited to the mud + water mayhem you might see off-road, as they attach externally. Most also mount to the crank. For a while I toyed with the idea of making a system that was driven off the flywheel, because I could mount the components higher up, but ultimately, I decided that the MSD/FAST interaction had some great benefits, like being stable and widely adopted/supported. So one approach is to use something close to stockinitially and then upgrade later once you get the motor running. Too many changes at once and you have a vehicle that sits for years because it is too complicated to finish.

My .02 cents, more or less on topic,

-Jeff