Welcome to the Team Jim!
Long roofs are cool. A lot of them where converted to use as ambulances and hearses stateside, don't know about in the land of Oz. An Olds Vista Cruiser roof with Chevy motivation would be a cool ride I think (It would be a poor example of a custom car to swap on a Chevy dog house in place of the Olds sheet metal and stuff a BBC under the hood, but that is just me. I liked the idea of a glass sky light for passenfgers in the back seat to look out.)