Paul, Ive had a few contacts through Ducati pipes they have made (I have a set of their "replica conti's" , I dont have them on a bike I wasnt overly impressed by the quality, nothing like the standards of Staintune thats for sure.
I have also used a local bathurst firm - HiTech exhausts out in the industrial park off the oberon rd , they custom made a set of large bore ducati 2 into 1 Gianelli pipes for my race bike. Amazing work. They had to make jigs , and fabricate the whole thing from nothing. It was expensive $2000, but what a pipe and a great result.
They could and would make you anything if you go out and se them. If you have an old set for templates etc that would probably lower the cose too.
Ask for Dwayne, tell him I recommended them, you just never know and they are local.
Hope that helps.