Albins Off Road (Vic),
Pfitzner (SA),
Modena (SA I think - might no do custom stuff).
Needham (Vic).
If it were a car box, that's about the order that I'd ring them. Dunno how their prices/enthusiasm levels change for bike stuff.
Modena does really nice work, but you pay for it...
And expect a wait, no matter who you talk to.
Be interested to hear what ColJen can do.