Avoid the SAFC's, as it taps into to the factory wiring. Eprom ECU (and a spare just because) socketed, will be the way to go. My preference is no piggybacking.
I bought an SAFCII, twice. I just didn't understand how easy it was to get another chip made for my expected airflow and installed modifications, including a dual runner Cyclone intake manifold.
If you go that route, we have a member here that can get you a chip setup, with lots of features, for a reasonable fee.
All those other parts will make the car quite fast.
I would suggest adding a transmission overhaul to the list of things to do, before tearing down the engine (if the timing belt is too old, worn or you have super excessive oil leakage).
Reason being, you are going to move the power band higher in the rev range, and where the motor is going to want to stay when you get on it.
This is where the older/worn out fibrous syncros in the early 89 Colt/Mirage Turbo and 90 DSM rear their ugly heads. They had a better shift feel when new (better grab with less shifter arm pressure) but wore out quicker when shifted in the high RPM ranges, for extended periods. Be careful to only use GL-4 trans fluids in this transmission also, GL-5 is too slick and will erode the non-ferrous metal in the syncro units. If you want to keep the dog teeth on the gears, intact, then this is where new syncro's comes into play. Food for thought. I'm rebuilding a trans just for this reason. I have never experienced anything but worn out, or close to worn out syncro's in two KM210 transmissions now. I am going FWD DSM now, to see what happens and to get away from the fibrous syncros.
Slightly stronger transmission, will drop right in after changing the shifter arms, and if the year is 91-92.5, it should have a 25 spline center diff to accept the turbo axle and halft/axle setup, or even an LSD with 25 splines.
Please consider adding your VIN to the VIN Registry.
General discussion, top of the page.
These cars keep popping up on radar, so it's uber important to get them catalogued while they are still active here.