How about the Benchmade 943? I have a 940, and am often looking at that as well.
And your idea of the ZT450 and abbazaba's Mantra 2 suggestion have also crossed my mind, as good knives of similar proportions to the 940. I think the Gemini, while perhaps in the same weight and length class, has a very different blade profile, being a much deeper drop-point.
You might also check out the Al Mar Falcon Ultralight, the Boker Plus Mini Kwaiken, the HK Nitrous Blitz (discontinued, but still around) though the Al Mars still run AUS-8 and the HK I think is 154CM.