If you talk to independant midwives, they may have one or know where you can get one. A Google search might lead somewhere, too.
I got a $20 pool from my local discount store which I plan to use.
If you wanted to buy a 'proper' one:
http://www.simplybirth.com.au/
Or try here for rental:
Birth Afloat
Heated Wooden Birthing Pools for Hire
Inflatable Birthing Pools for Hire and SaleWater is the most natural form of pain relief. Being submerged during labour is soothing, relieving, safe and cosy. Baby’s are born into a familiar atmosphere of water and are generally calmer when they’re born. Drug free births are more possible in water.
My pools are specifically designed for the birthing woman. They’re very easy to erect and the wooden pools come with heating elements so you don’t need to be concerned with fluctuating temperatures during labour. For details contact: Maureen O’Hara, 02 6684 9222
0429 668845 or email moh999@bigpond.net.au