we're not supposed to say other sites on here, but
this site has an australia regional board...
as for engine mods, you can put a jdm b20a in for quite cheap... it's a drop in replacement, so if you're comfortable with pulling your engine, you can put it in yourself... jdm b20a's go for about $650 US shipped... i paid $1800 US for my engine and installation, but i replaced quite a few parts that you might not need to... paid about $800 for labor and tax, the rest was for the engine and parts...