At this point, I'd talk to few tuners and see what they say about your setup and your power goal, and go from there.
Changing fuel pump and injectors wouldn't yield more power BUT will give you extra fuel to feed into motor so you can raise the boost to achieve 300rwkw (I achieved 302rwkw at 90-96% injector duty - not recommended), you'll need Nismo AFM for better resolution (again, talk to tuner they should explain you better).