I use "too broad" as the close reason for questions like, "Does a tool for X exist."
Of course, when the question is taken literally, the answer is simply "yes" or "no" - but in practice, as you noted, it's a request for resources and so there could bybe any number of equally valid answers.
Rather than adding a separate close reason, would it do to edit the description of "too broad" to more clearly encompass this category of question?