I have packages coming monthly; ordering from ATS Racing, Racer-X, Prime, TwosRus, Real Street Performance etc through a freight forwarding service that seems to be cheaper and also collates parcels into one. Restricted to $1,000 aud (inc freight) per shipment.
Australia has some good suppliers in aus like WTF Auto in WA, Gorilla Imports, and sellers who send to Australia directly like Amayama & Ebay (EBay global shipping) - many more. However depends on what part you are chasing, weight, sizes etc as what works out.
I am located in Brisbane if someone needs something sent (conditional to the part/cost) PM me.