ZX9R big bore suppliers

Can anyone point me in the right direction for an engine builder in Sydney/Central Coast area who would be competent do the machining for a 950 big bore kit?
I have heard they can have dramas sealing the head if not done properly so I would like someone who has done them before successfully. Also want to get the crankshaft lightened and balanced if anyone can point me in the direction of a machine shop who can do that work?
I have heard they can have dramas sealing the head if not done properly so I would like someone who has done them before successfully. Also want to get the crankshaft lightened and balanced if anyone can point me in the direction of a machine shop who can do that work?