And you need the Postscript Fonts, of course.
I believe Ghostscript development has moved. You should consider the very latest incarnation, version 8.00.
This and all the associated Fonts/files can be found
HERE.
Note that there are some unresolved issues with IB2.3 and Postscript printing. I believe it has problems with tables.
Anyway, you can get all the lowdown straight from the horse's mouth by joining the
IBrowse Mailing List.
Cheers,
JaX