Just for the newbies and keeping new parts at a reasonable price;
Amayama is cheap for Toyota genuine parts - delivered to your door.
PrimeMR2, ATS Racing, Twosrus will ship to Australia. They ship express and insured (costs money).
MyUS is a cheap freight forwarding service, so the above suppliers can send to the MyUS and they freight forward in cheap rates including insurance and no excess for size restrictions like other freight forward services.
Australia charges high fees for having grape after than $1000 of item brought in one package.
There are reasonable priced Australian suppliers like WTF auto, Gorrilla industries.
eBay (especially with eBay global shipping) is cheap.