I have thought about this contest as well. With the deadline only 8 days away, I don't think I will put anything together for it. Besides, there are only two winners nationally and I imagine that the competition will be too stiff for me to be in contention. All of the previous winners have been university or graduate students and I am a high-school peon.
To get back to your question . . . I think that a dialogue would fit the prompt and the situation just fine. I imagine that they get get quite a few entries written in dialogue. I don't think it would be too different at all. There is no need for a disclaimer. Now if the conversion were *real*, then you would need to let the panel know that. They are asking "if" you could have lunch with someone, who would that be. They even give you the option of dining with a famous person who is dead. No need for a disclaimer on that one!
Eric Noto