Hi Mas,
I can't speak for Sydney, but if you are prepared to make a day trip of it, come to Canberra and see Andrew at Capital Steering and Suspension.
He owns a 3200GT, has completely rebuilt mine, another 4200 and did wishbone work on another GS all in the last 6 months.
He has raced rally cars and knows how things should be set up.
PM me if you want and I'll give you his details.