Speak to your workshop, they can best figure out what's the go with the aftermarket parts.
Once it comes out of compliance, you need to take the following to the RTA - Engineering Cert, copies of the Import Approval and CIN documentation (the import paperwork), weighbridge ticket, blue slip. Usually the workshop should be able to arrange all that for you.
Get green slip beforehand, go to RTA, pay fees for stamp duty, registration and number plates, and off you go. Don't forget to sort out at least third party insurance, and an immobiliser as soon as possible.
Details are also here in case you need them: http://www.rta.nsw.gov.au/registration/get...edvehicles.html