Try uniqueautosports.com.au. They have the dumps for $395 + fitting or $500 coated. I'm going to give them a go with my cressi. I already have the rest of the system in 3" from that horrible cast piece.
The unique auto sports dumps are a big improvement on the factory exhaust but are still not the best.There is a exhaust shop in girraween sydney that makes a great set of dumps for the 1jz. Im not sure of the name or exact address of hand but i can find out for you if you like. There just down from sss Automotive on gilba road.