Maybe have 5-10 players and the rest are the fools who run into the cornucopia and die right away. 4 of them would be carriers. You should be game-maker so you can control events.

You can start with the reaping as part of the character sheet with who was called and how, what district they are from, who says goodbye to them.. etc. Then for introduction posts it would be the first interview that's publicized before training.

Just some thoughts =]