[Guess who is in Azalea too! It is very clear to see that Itachi is in the same place by the background of the video. He's further in the city though.]

The gym leader in this town specializes in bug type Pokemon. I believe the name of the leader is Bugsy.

As for obtaining an Eevee, I am not entirely sure. I have not come across one in the wild, though I am interested in the potential one seems to have.