As I understand it you can run a non-standard ECU in QLD only if it passes an emissions test and runs closed-loop permanently.

A 4AGZE into RWD looks like a better option than a 20v purely because of the distributor thing, from pics I've looked at the 4AGZE has the distributor off the side rather than the end like on the 20v.

Don't quote me on this, though, as I've been wrong before...