stock internals are good for around 260-300rwkw, depending on condition, dyno etc. sometimes more but then it becomes a question of how long it'll last.
have a look at your afm and see what colour sticker it has on it. green is stock silvertop/s1 25, pink is stock s2 25, ornage is z32 airflow meter and yellow is q45. z32 afm would be fine for what your after.
as for injectors, if you dont plan on ever building the motor then some nismo 555s will do nicely