If you could find parts for the Straight 8, I would imagine they would be quite expensive!!! You might check with Egge, they make a lot of pistons for obsolete engines, not sure what other parts they handle.

A supercharger would be kewl, just plan on fabbing everything yourself.

Might be better off financially with a late model engine. Kind of defeats the "old school" run what ya got premise if you have to stick a ton of money into it....JMO