Hmm... Amia and Eddie would come off as intimidating since they're also Poison. If we really to be intimidating, I'd recommend sending in Amia since she's fully evolved... Sam would be least intimidating, unless we wanted to go with a non-Grass type.
...Maybe it would be wiser to not approach Nairek quite yet at all, instead interview a few Pokemon with them as the topic, and see what we can learn...