Have you checked with the corps for reccomendations?

Are you experienced enough to live in a down bag all summer?

Lastly - you should learn to sleep more warmly in a lighter bag. There is always something that you can do to be warmer. Never sleep naked in your down bag.

I really think you need more experience and less sleeping bag.

These are my own opinions based on wisdom earned through many wrong decisions. Your mileage may vary.