Adjustable fuel pressure regulator is a real easy way, but really the SR stock tune runs really rich as it is IMO.
ROM tuning is another easy DIY way too.
But please, PLEASE stay away from that SAFC, it accounts for damn near 70% of SR failures out there... Because people are dumb shits and think it's a magic power making device and allows them to jack their boost up to 1.5bar with out bigger injectors.
Most people just don't realize how an SAFC works, it does more to your ECU than just change fueling.
(I hate them with a passion BTW, as if you didn't notice already)