Ben, as Ash said, if you only want 300awkw, then you want to use the most responsive turbos you can that can achieve that power and the simple answer to that is a set of GT-SS's.
You also wont need a Power FC D-Jetro, and even if you did choose you use one then you wont need AFM's anyway.
My R33 is comfortably producing 320awkw with GT-SS's, Z32 AFM's, Sard 700cc Injectors, Tomei Type B poncams on a VERY conservative track tune