We are choosing our flights from LAX to EZE (Buenos Aires) for December 2019. American Airlines has a flight that meets our criteria with a layover in DFW. I'm looking for advise on what I should be concerned about. I'm assuming since we are staying with the same airlines that our luggage will be transferred but what about having to go through security again since this is an international connection and how long of a layover is long enough, our options are 1.5 hours, 3 hours or 4 hours. Thank you!