I didn't even have to go looking for my belts.My auto electrician noticed my belts were worn when he was working on my altenator, and asked if I wanted to get some new ones.I said "sure!"He sourced and bought them in for me.Got them the same day so they must be available locally.
The altenator belt park number is 5PK0955 (Dayco)The AC belt is 4PK0970 (Dayco)and the Fan belt is 6PK1300 (Bosch)
Any spare parts retailer should have it, or be able to get it in for you.Alternatively, if you still have the belt, you can take it in and they should be able to match it up for you.Hope this helps you out.
PS: As for the source for parts, you can use http://www.infinitipartsusa.co...id=55. Joe usually gets the parts to me within 5 days or less, from the USA.
Otherwise, use the yellow pages online and search for "auto parts recyclers".I am not sure about Perth, but we have a few import wreckers here in Adelaide, and I sourced my altenator from EKW in Victoria.
http://www.ekw.com.au/
Of course, you can usually get everything you need from your local Nissan dealer, as they will bring the parts in from Japan for you (as necessary)
Good luck.
Modified by ozzie! at 9:03 AM 1/4/2009