I'm slightly loving that the Grey Knights have a character called "Librarians". This makes the geeky be-spectacled part of me kind of thrilled - librarians as kick-ass heroes? Go!
And the Grey Knights also have the Jokaero, an alien race that looks not entirely unlike an Orang Utan.
I'm sure any Pratchett fans can see where my brain is going with this, but I'll fill in the punchline anyway - get a Jokaero model and play it as a Librarian. And introduce a new rule where it goes berserk if anyone calls it a monkey...
(Googling around,I'm so pleased to see that I'm not the only person who had this idea. C'mon, I'd be worried if I was...)