I would heartily recommend a light port & polish, essentially cutting away flash and smoothing the bad casting in the intake and exhaust ports and the transfers - as well as the easier but essential matching of the intake and exhaust to their manifolds, including the gaskets themselves. Despite the relative "complexity" of a "serious" port n'polish, what I'm describing is truly easy for those with a lil patience and a touch of caution (like not cutting too much or scoring the cyl walls is all), yet the gain is usually quite pronounced.
I figure it like this - tho alla goodies you describe are indeed worthy, their effect is somewhat lessened when bolted to a motor that's not been "cleaned" in this fashion.
Examples of untouched sloppiness (click to view)
after jus' a few minutes with the ol' Dremel