I am thinking about replacing my injectors, the engine is stock, what's the best psi rating to go without modifing anything, also suggestions on brands would be helpful?

 

The stock fuel injectors are rated to flow 24 pounds/hour of fuel when operated at 43.5psi differential pressure (stock vacuum compensated fuel pressure regulator). If you replace them, you have to match the flow rating. If you change the injector size you have to have the PCM reprogrammed with the new size.

Why are you "thinking about replacing" them? If you did get larger injectors, they would not affect performance at all, since the stockers are more than adequate for a stock engine. If they aren't broke, don't replace them.