I did 150K miles in a Merc C230 Kompressor and I never had a problem with the sound of the Eaton supercharger. You could hear it kick in (electro-magnetic clutch) at around 2000 rpm, but it wasn't intrusive.
1Gs are 2-litre. The Aussies reckon that the limit of the Aisin SC14 supercharger is around 225bhp.
The power curves posted above demonstrate why I can never see the point of centrifugal blowers - they always look like the worst of both worlds.
If I had the fabrication skills, I think I'd go for a TT 1UZ (or perhaps a 500bhp LS3 crate motor ).
If I didn't, it would be a positive displacement or twin screw blower kit on a 1UZ, a 1JZ-GTE or 2JZ-GTE transplant, or NA-T.