Hey Jason,
The type of conversion that you are talking about as the second choice will still cost you around the same money.
You can get a diff ready to bolt in from V6 conversions for around $900, front end Hq studs wont fit commodore, from what I have read here previously I think that the HQ is about .5 mm out and will break studs so I would recommend a Hoppers Stoppers conversion, also around $900.
Have a look at
http://www.v6conversions.com.au and see what needs to be done. then if you are still unsure at least you know exactly what will be required.
You are going to need an engineer regardless of which way you do the swap, there is around $1000 also.
Hope this helps.
Cheers
JB