Hey,
I'm only new on here, but was linked to this thread and thought I'd contribute some of my limited knowledge.
I notice your discussion about the roots style supercharger, and their inefficiency. I don't believe a word of it. I've taken this next section from a company website, of whom I know the owner, and I also know he has a good knowledge of what he's talking about. Whilst it does have some advertising propaganda, it sheds some moe light on the issue. (Note that this guy sells Magnuson superchargers, hence the references, although he also sells Eatons)
I hope that sheds some more light on discussion at hand. Good luck with your project, I'm contemplating a similar thing only to my Alfa (Sssh! Secret!), so it's always useful to read more info from other sides of the manufacturing world!
ROCK ON
R~R