Here's a bit of an update. Could've posted this last night, but I spent most of the day playing Modern Warfare 2, so I was kind of pooped! :p
I decided on going with Chief Aramaki, simply because his skin is pretty different from Motoko and Batou's. Motoko's all about beauty and youth, Batou's skin represents hard edges and a bit more dullness (though I'm still trying to strikes a balance between this and the idea of artificial skin), and Chief Aramaki's skin represents a much more matte like quality and less vibrant colors. If Batou wasn't my favorite character in GitS, I'd probably have chosen someone who had actual eyes, so that I could show the same sort of range of age degradation as I'm trying to do with human flesh. But I'm still having a lot of fun with this! :D
Still a WIP. Hoping to finish it all up tonight.