Depends what you want the letters of recommendations for. If it's for the application, the application is very specific that is MUST be certain teachers, and 1 teacher of your choice. If it's letters of recommendation that you want to present to your congressman/senator when applying for a nomination, then I recommend you make it well rounded. Academics, local community, and business community would be 3 really good areas. If you know someone in the judicial/legislative venue, such as renown lawyers, or others that the congressman/senator may also know professionally, that too could be good.
Again, it depends on what you want the recommendations for. The ones the academy wants, is already decided for you. You don't have a choice on those.