the only difference between na and turbo rb30 heads is the cam.
the only differences on the whole motors na to turbo is pistons(different compression pistons), oil pump and cam.
id say put turbo parts on the rb30. na cam will be ok. standard high compression rb30 na plus turbos are pretty good. put turbo computer and injectors on but.
will make more power than rb20. both being pretty standard
different cams for rb30 are only couple of hundred i think or even get a regrind. youl be able to go pretty good for cheap. keep it rb30