MicroSquirt
This is one of the smallest standalone engine management systems available, and at $339 with a wiring harness, its a no-brainer for your basic combos. This ECU was designed for powersports applications - watercraft, motorcycles, etc. But its small size and rugged construction also makes it popular with people who want an ECU that's easy to put in an inconspicuous location, like street rodders, or racers who want an ECU that will stand up to harsh use, such as road racing or dune buggies. This unit has two fuel outputs and two spark outputs, a PWM output for idle or boost control, and two on/off outputs. It's possible to reconfigure it to use the extra on/off outputs as spark outputs as well. Although most users will have somewhere from one to four cylinders, it can be, and has been, used on V8 applications.