Apart from my feedback above I find the general shape of this concept pretty good. For the surface, real world aerospace materials might be a good source of inspiration. Titanium, carbon fibre, something like that. I guess what most of them have in common is the smooth and "clean" look with a moderate shinyness. But don't spend too much time on that, a texture can easily be optimized on the finished model, the shape is more important for now.
Does this give you a better idea?