Classic power steering pump advice

[Scott v-limited]

Hi everyone as you can see from my profile I have a 1996 v-limited import 65/1000. I'm in need of some advice regarding the power steering pump. I've had 2 second hand pumps fail now so it's bout time I sorted the problem proply. Just wanting to know if anyone knows where I can get new pump or maybe upgrade to a newer model so I don't come across this problem again? I also want to refurb my rear diff with new gaskets etc but I'm unsure which diff my car has. Either 160 or 180??? Cheers fellow Subaru addicts