It would be more efficient to view your stars inside your level design. Your inner gradient looks perfect, but to choose which border fits the best, I would say it is depending on the context you will put it in.
Anyway with a white background, my fav is definetly n°2. Mostly because a "dark orange" border enhance your star gradient well. Another point to notice: I would not use a complex border design - It is definetly not what our eye needs to focus on, right?
Hope this help.