Well there's the plastic generic Librarian for a start. If you can find him there's also the plastic Librarian from Dark Vengeance.
There's always the Grey Knights option; back pieces have a psychic hood, pads and chest pieces have sword through book designs which sub nicely for the horned skull as a Librarian symbol.
What sort of Librarian bits are you after specifically? There are loads of key, scroll and book bits throughout the
GW range (before even considering third party stuff), which can help denote status.
As an aside you mean current scale bits, despite the doom and gloom regular marines aren't obsolete