It would be easier, I've never really looked into 8v's much, but you'd need pretty much every bracket, hose, pipe, wire and bolt off an actual G60 engine to do it, (if you can infact just supercharge a normal 8v)
So you'd be best off just buying a whole engine, or a Corrado donor...
If it was as easy as you imagine to fit a turbo/charger to an engine, everyone would do it