I'm fine with you calling it calibre and explaining its non official status in the description. I've never tried building a 64bit version of calibre on OS X, so I can't really say how good/bad/ugly it is. I d recall various problems being reported on various mailing lists with getting 64 bit python, Qt and PyQt to play well together.
Just put me on as a maintainer, in addition to yourself, no need for anyone else, as I do all the dirty work of build system maintenance in calibre
