The problem with adding more Duros is part of an overall theme of my NPC Overhaul style mods.
With the tools and resources we have today, I believe it's possible to give every NPC in the game a unique appearance. The problem is that we don't have enough NPCs for all these possible unique appearances, with the limited number of Duros who appear in Kotor and the possibility of future Duros skins (albeit unlikely) it might be very difficult to implement more Duros with the ability to wear Armors.
And as for a K2 variant, I can foresee a few issues with that. The Duros' lips don't move, this might just be a bug as a result of porting JCarter's head model to K1 or maybe JCarter didn't bother/didn't know how to make the lips move when he originally made the head resource. If the Duros' lips don't move, this won't work with an NPC like Samhan Dobo who has proper in-game dialogues.
I do intend to port most of my K1 NPC Overhaul style mods to K2 at some point, however, for now I'm simply sticking to K1 as I still have more mods to make. If I do ever get around to porting this mod to K2, I would have to map out & decide which NPCs will get a Duros with armor appearance (Off the top of my head there aren't many contenders who could use a Duros in armor).
As many of us can guess, this mod is rather basic... whilst it would be possible to create body variants with new alien hands or reshape the entire model entirely to fit the Duros structure, I'm afraid that is beyond the scope of my modding capabilities.