My additional 2c (so, my 4c?) is don't worry about what boost pressure you want to run
People get fixated on "I want to run 20psi", or whatever number they have picked
End of the day with a bigger motor, which breathes better, you might not -need- 20psi to make the number you wanted anyway. It's purely an example of how much restriction there is to the turbo pushing air in remember, so if you have a more efficient motor to start with, it's less restriction, so at the same airflow you show less manifold pressure (sort of)
Hence why you can make such easy power on a turbo honda motor (for example) compared to having to push 2 bar into a beat up 8.0:1 EJ20 to make the same on the same turbo. Ditto for how on some cars a camshaft change can net huge gains, again it's making the base more efficient, which then snowballs once you add boost. More capacity is the same, combine both for max win