1. Try Phil at Direct Imported ... he's a sponsor of this site.
www.directimported.com
I got my car through him, as did my brother and my ex girlfriend. All cars were/are great and I couldnt recommend anyone better.
2. There are heaps in Perth. Do a search. X-speed, Hyperdrive, Supertec, Speedworks, blah blah blah the list goes on.
3. Again, search. Carmate has heaps but don't know about their quality?
Works Auto in Perth sells some too.
Hope that helps somewhat, and good luck.