Even though it's a Peugeot, we need to know which engine you have. Letters 6,7,8 of the VIN would help, eg RHR.
Firms like EAI can usually help, if you quote the VIN. Sydney 02 9481 8400.
It will also depend on whether the car has a pouch or a tank. The reservoir is under the passenger's side in front of the rear wheel. Aftermarket can save money, but cerium compounds aren't very cheap.