i think its a waste of time for your application to port/ polish, they are generally great from factory, maybe a lil clean to get rid of cast blemishes.
valve springs i would recommend, even tho i dont think its necessary for your power application.
i used 256 pon cams, straight drop in no mods needed. the larger stage 3 cams need machining to fit.
saber in perth did my head work, they are very good, pm me and i can pass on my details
good luck