Castle Hill Exhaust is a no go. I would steer clear. They did an exhaust on my mates d22 and it was rubbish, didn't wanna know him after they got their money.
I put a post up in a similar vein recently and the company recommended was in Wetherill Park. It would be in the D22 engine section regarding tuning post chip.
Can't remember if it was West End Diesel or Sydney diesel that was recommended - haven't been yet, but they recently opened a branch in Castle Hill.
Edit - it was West End Diesel and you were one of the people who recommended them????
There's a mob down here in Canberra if your up for the trip!
Turned a nates ranger into a beast!
And it'll give me an excuse to throw the muddies on too