i agree with Tim, turbo the G60 :)
or maybe import a Bahn brenner changer (man i love the sound on these)
I personally do not like G60's due to the fact everyone i know who has owned on they have all let go! (and i know alot of people who own them lol)
Did you mean Twin screw or bbm ported glader????? i have considered a twin screw (dreamin) but having not heard one in real life i am afraid if i got one (dreamin) it would be too loud are they as loud as it seems in pics.
Bahn Brenner Motorsport - Superchargers
YouTube - Mk1 g60 running a Bahn Brenner charger...
its pricey but i love the noise :)