Others on this forum have suggested that what on paper looks like a poor performing public school might actually be a good fit for a gifted kid in that the kid will stand out so much that it might be easier to ask for and get special accommodations. That is to say, the school might be less likely to give you the standard "all of our students are gifted" brush off. I don't know whether anyone has actually had this experience, but it always sounded convincing to me!