Are you moreso concerned about spool time? (going by the other turbos that are brought up)
You said you are looking for 280-300whp, which in most cases won't require 15psi (depending on the turbo).
My 1st suggestion of a 60-1 came from me building a kit on a RSX-S using a cast manifold and 60-1. I never got to dyno it, only street tuned, but the car absolutely ripped topend (after about 4k)