Nomenclature would be 33B.
Also, stealth nekos are in use. Reika certainly used the NH-33S. Kotori was a NH-29S (on paper, anyways, before I plotdeviced her).
In all honesty, I'm not sure I like the current direction of this discussion. It kind of ignores pitfalls of previous models that were explored before, and there were reasons for the current directions. A "fresher" point of view might not perceived how we've "been there, done that" already, and I'm not optimistic about rethreading this.
But, the nekos are Wes', so, have at it... I guess.