2 things jump out right away for me:
Custom Front/ Dump/ Screamer Pipe
Catco Straight through Cat
if u get caught with the screamer, u'll be ordered to plumb it back in, and with that 'hi flow' cat ur gonna get ass reamed if u get caught.
just dont drive it at full noise on the street in populated spots and u should be fine.
also ride height, no part of the car can be lower than 100mm off the ground
another thing, u dont need to worry about emissions, caus they dont test it in qld, but they do test noise levels every so often
oh and for rego in qld, u'll have to get a road worthy, AND u'll have to pay stamp duty, again