Im willing to bet it is your pump and not your injectors i got my car tuned and it showed up around 80% duty cycle with 600cc injectors and was making only 245rwkw with 14psi...changed the pump, finished the tune and it showed 306 rwkw at 18psi and the duty cycle went back down to high 60s
On to the turbo I had a 3076r with a .82 IW rear made 306rwkw at 18psi and 260rwkw at 14psi it was quite responsive though i did have poncams to help, all up it was a nice linear turbo on the street not so much down low that it would wheel spin all over the place and not too laggy