Engine Management Question

Okay, Here's my question. I have a 1994 Subaru WRX Wagon (5sp of course) So far I have an Intake, Exhaust, and Turbo Timer. I have an HKS PFC F-Con, APEXi S-AFC2, and an APEXi AVC-R. I can't find any useful information about the PFC F-Con. So here's my dilemma. Since I don't know anything about the capabilities of the HKS unit, I don't know if I should install the HKS PFC F-Con or the 2 APEXi Units. Also, does the F-Con effect the boost level? Either way I'm going to have it tuned on a dyno. Thanks for your help,
-Eric