Well, this does not seem to be that easy, right ?
I thought about your question, and I must admit that I have close to no clue on what to do.
Maybe you could sculpt some on you own, using this green stuff they offer at Games Workshop, adding some wire in according shape and thickness (0.4 or 0.2 mm) ?
Converting existing figures, maybe even upper bodies of infantry signalists, could increase the range of different postures, at least. But as Napoleonics usually are totally into this uniform accuracy thingy, this might not help you, right ?
Marc