You really won’t know which cabin you will receive until the tail number has been assigned to your flight, even then it could swap until the end. I would recommend making a seat selection you would be at peace with in either cabin because you really have no control on which one you end up with. More have the newer all-forward super diamond seat with the fixed screen as you mentioned, so the odds skew that way.

from SJU-CLT you can expect a cold meal on a tray, of very mediocre quality. Just check the recent entries on the domestic meal thread on here for examples.

Enjoy your trip.