Repco or Bursons or someone like that would have the bits if you want to start doing things yourself. Replacing the slave on a car on stands on the floor is a nasty messy job though. Workshop manuals are in the Technical Guides section of this forum.
It would be worth asking them to flush the brake fluids at the same time and check brake pads and rotors too.
After that I'd have a close look at the car's service history and see what needs to be done to bring the rest of the car up to date.
Oh, and welcome to the forum.
