All men have different preferences, yes, even in little things like hair and eye color. And honestly some hair lengths look better with different hair colors, and hair colors look better with diffferent lengths and styles, etc. AND every man's opinion on that will be different.
But I love dark brown eyes(I have dark brown as well) and dark hair is awesome with dark brown eyes :) And a bob isn't too bad, but I prefer shoulder length because it shows more motion and life I think. And all the dark shades have beautiful contrasts.