well, that question there is a good example. let me explain.

30psi is pretty ambiguous
what you want to talk about is lb/hr or cfm.
30psi on a turbo that flows 800cfm is a whole different ball game than 30psi on a turbo that only flows 500.
You're talking a huge difference in airflow and in turn horsepower potential.
That in itself shows me that you still have a lot to learn which is why I said I think you're getting ahead of yourself.
I could go into a similar argument on compression but you get the idea.
Don't take it as an insult, because it's not. It's just advice from me to you. Ultimately its your car and your money so you do whatever you feel is best.