Hi Ross,
Where abouts in Perth are you?
Jason has now sold For Parts so no real alternative to Minicraft which is a real shame because lack of competition certainly leads to some very large and expensive 'hiccups'!
Veale stock a lot of engine parts such as bearing etc. Minisport in Adelaide have good delivery times for parts while Minisport UK are great for price and selection. Machining I highly highly recommend Performance Modifications in Osborne Park, they do a lot of work for Wilf Chambers also in Osborne Park, he is also very good and specialises in anything British.
Other than that this forum is excellent for advise and people willing to help with most mechanical issues you may have. Some of the Perth gurus are Jason (Babes) and Rodney (Boomini), both very knowledgable, friendly and always willing to help where they can. I'm always good for beer n BS

Marty