[ts77]

heh, its not rpm, not that easy , but their comment on the bugs-page makes me think that they have no general problem with closed-source packages.
they use plain tar.gz packages which are installed with ebuilds unfortunately I don't know enough about them to help in this regard.
I guess some paths and such need to be adjusted too so that they fit into their scheme.
Maybe you could try first to contact someone there to make sure that you can integrate it so that its worth the effort for making an ebuild.
Guess the lists http://www.gentoo.org/main/en/lists.xml are a good starting point (at least there is a dev-list listed).