Thanks, Bo. I sent an email to all three of them (I have one guy communicating about getting a letter of invitation, one guy who copied me a visa application he had made (with my birthdate December 2008) to which I had to tell him was incorrect (I'd certainly be the youngest pilot on the roster) and another that sent me, out of the blue, a reservation!
Seems grossly disorganized. I didn't hear anything on the forum for several days so went ahead and politely told them I needed several weeks lead time, since I have to buy a ticket from Hawaii to Washington DC, which is where the reservation was from, and last minute fares are equivalent to scalping.
I haven't hear anything back. I just wonder if they are all on the same page there.