Heh, you don't have to pick the least popular species. Just ones that don't appear a lot in FVNs that you'd think would look good. Then again, according to Kopten's FVN species diversity sheets, camelids and platypus are the least common species in FVNs, (though keep in mind that avians, reptiles, and marine mammals are all each their own category so specific species from those categories might be even rarer if not non-existent) so maybe you can come up with interesting characters of those species. But I'm glad you think the VN stands out!
Hopefully you'll enjoy the VN when you get to it :D.