Assuming you want to do Black and White printing, I can think of 3 off-hand. Others may know of some more.
1) Pointlight in Surry Hills
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2) Blanco Negro
http://www.blanconegro.com.au/
3) Australian Centre of Photography
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I use number 3 as it is slightly cheaper than the others, particularly if you buy blocks of time. The facilities are fairly standard. LPL 7700 B&W enlargers. Kodak chemicals are used and are set up by the staff. I haven't tried the other 2 but they appear to be quite reputable.
Best regards,
Thanasis