Have you ever heard of toribash? If you use a bone system similar to their model, you can vastly reduce the number of bones you have to keep track of. And honestly, you can just subdivide the more flexible pieces until you're satisfied, but still, you shouldn't need anywhere near 64 bones to satisfactorily represent a person.

Using hodgman's calculations, you could (in theory) cut the packet sizes to a third of what they were, so.... 0.5M per client and 17-18M for the server?

Also, it may just be me being silly, but can't you somehow not have your server send all of the packets to every individual person? I thought there was a way to save bandwidth or something, because that seems slightly unreasonable... I'm lucky if I get 4-5M down, seriously.

Good luck,

Selenaut