If you are uncomfortable providing any sort of outline or anything, just make notes for yourself to keep you on track. Sometimes under pressure it's hard to remember what you wanted to cover or even if the topic goes off track for a while you can look at your notes to remind yourself what things you planned to cover.
I think that if you give too much information on what you intend to cover you may be going in to fight a battle (particularly if the administration already has their set feelings on things) with negative feelings and attitudes from the receiving party before your points can be made. I think it would be best to provide what you plan to have a meeting regarding without going into too much detail until the actual meeting. I know particularly with private schools or parochial schools, that are not required to abide by the state laws regarding gifted education etc (at least in my state), you may have to work a little harder to fight your battle as they really don't need to do anything for you (sadly).
