New alternator bearing you could get done at the place on Carlton rd in Gawler, cant remember thier name but they are an electric motor rewinders. Water pump, better of getting a new one through Nissan, dont go for the cheaper option they're shite also dont belive parts guys when they say RB30 is the same. Power steering pump would have to be taken to someone like ReCar at St Agnes or similar.
I'd start with the alternator and maybe water pump. Only down side with the water pump is you have to take off all your timing belt cover, harmonic balancer(unless you can get the bottom cover off without removing it),and timing belt.
Hope it all goes well for you Penny