I sue the SAFC with an Aeromotive fuel pressure regulator with pretty good success. You will be battling the stock ECU - particulary with resepct to ignition timing.
I wrote up a tuning guide after doing some videos for the installation of a regulator and how to tune it:
http://www.lovehorsepower.com/MR2_Docs/Tuning.htm
http://www.lovehorsepower.com