I don't want to splashing out on something that may turn out to be illegal or get me defected.
Cheers guys,
Matt
You have answered your own question here mate. If you want to be sure you are always 100% legal then your only choice is the Aust. spec MR2 engine.
But there is no reason the 3rd gen can't be made to comply with a cat con and careful tuning, if you want to go to that level and find the right guys with the right gear to do this.
Certainly, paperworkwise, the MR2 is the best choice, but given that you are just replacing a 3S-GE with another one, do you need to "declare" it at all ? Isn't it not just a notification of the new engine number ? If that is all then go the 3rd gen 3S-GE and enjoy the extra power !