I voted for the Sleiti, which are tied for second place.
But as I look back at the sole (but awesome) miniature in that section, I can't help but think of a dynamic pose of a Ieuan doing a single-handed cartwheel off his left hand and confidently taking a shot with his biological, wrist-mounted weapon. I see the Sleiti as elegant, but also quick and gymnastically inclined. It'd probably look like something from The Matrix--the shooter being calm, unconcerned, unsympathetic, and totally unphased by the otherwise hugely awkward position.
I'm not sure if that fits their concept (and I'd love to see more basic units), but that's what I see.