I believe there is one that is MSP specific, called PSC1-020. This is the one Protegegarage carries, but they show up used on the forum all the time. You can't use any of the other PSC1 ones because we have a high voltage MAF signal that needs to be divided, and there may be some O2 clamp trick it is doing to actually put the car into open loop. But unless someone posts a screen shot of the Torque app or other OBDII software that clearly shows the car is in "open loop" status under 4200 rpms, I will stand by my ground that it is impossible and the clamp just reduces the voltage to 0 forcing the PCM to add fuel.
The SSAFC has the most support here, but its software is seriously antiquated. Skim through the 100+ page ssafc thread to get an idea if that is the world you want to enter.
I had the AEM FIC for about a year. I had it tuned very well, but it took a ton, and I mean a ton of learning. The major advantage it has over the SSAFC is it intercepts the actual injector signals, so you can actually see what your car is doing. The SSAFC only does MAF manipulation. Also, the AEM has other inputs so you can graph your wideband along with every other input, which is invaluable. However, there were two circumstances I was not able to tune though and it really bothered me. I am fairly certain no piggyback can tune for them, so I sold the AEM and went to work on building a megasquirt.
The megasquirt is a whole 'nother ball game. Possibilities are endless but the information for it is immense, unorganized and many times conflicting. This is only for serious hobbyists, and why my car is still not running with it in. I am waiting until I have another daily driver until I attempt to do the full install (only inputs hooked up right now). My goal is to one day provide clear and concise instructions for putting one in an MSP in a parallel configuration so everyone still has their gauges and passes emissions, but please don't wait. I could very well get my new car and lose my desire to "perfect" the MSP.
Regardless of what route you go, there are a few things you will definitely need to do it right, and they are not cheap. One is a patch harness. You don't want to be doing all the work in your footwell, and you want to be able to quickly go back to stock, especially if you ever want to sell the car. Another is a wideband O2. You will want to be able to datalog this as well, so you need one that can datalog or a device like the AEM that can accept an analog signal. And lastly and often skipped is the OBDII scanner. There is no way you can tune your car without seeing your fuel status and trims. I really don't know why none of these tuner companies don't make a piggyback with an OBDII reader builtin, but they don't. The cheapest route is a generic bluetooth ELM327 device and the Torque app if you have a smartphone.
Whatever you choose, good luck.
