I've seen various topics through Google on this conversion; but I'd rather ask my own question

I have a '97 MK3 CL (Auto) and have fallen in love with it - lots of sentimental value, so I could never sell it; but I want something with more.. 'oomph'.
I've driven a few VR6s and love the power they produce, so I thought "Well, they are pretty much the same car, why not put a VR6 engine in it?!"
So that's why I'm here. I know barely anything about cars as it is and want to learn! I wouldn't do the conversion myself, because I'd blow something up.
Questions:
Would buying a plain old VR6 motor and simply putting in mine work? (I'm in Australia by the way.. just in case)
Would it simply fit in, or do modifications have to happen?
What other important things would I have to worry about? (eg. alternator, gearbox etc.)
Any other important facts you can think of, let me know!
Oh, and if it's as 'easy' as slipping a VR6 motor in, what would the technicalities of buying a right hand drive be? Any difference, or were they made universally?
Cheers!