I was quoted $280 to $380 for full rebuild (bearings (which are noisy on mine), rewind, regulator, brushes). They said the regulator part was $120 on its own.... I know with some of the bosch alterators the regulator is mounted externally and contains the diode pack and brushes - no idea if the nissan ones are integrated like that since they're internal, but for you guys getting $110-150 quotes i'd like to know what that covers.
WRT to air con rebuild, there's no rebuild kits left for R32 GTR so the only choice is new from Nissan. I dont know if 33 GTST is in the same boat but there was a group buy for re-gas a while ago - Frosty Auto Air, Bass Hill, 0418 608 680 - he rebuilds and he was the one that told me the 32 rebuild kits are all gone. He does good work.