Stock injectors will be fine for 250rwkw, like i said, got 2 mates with gtst's who both run 2535's, make about 250rwkw, very responsive... both on stock injectors...
HeathGTST owns 'MSPEC2'... DentonR33's old car... is one
the other one is on the forums as MSPEC i think....
I don't know about the GTRS or other turbos... i just know what my friends used... and thier cars are very quick.... they both run PowerFC's tuned by RacePace.