If you want premium cabin experience, then redeem them on non AA metal like CX, BA etc.
If you want to go to EZE, on the return flight, may I suggest a "free" stop over in DFW as a NA gateway and a free one way later to say, OGG/HNL.
You can use 17.5K miles in coach per person to get back to the mainland on the 2nd trip. Or pull 20K UA miles per person to get back.