Brian --
I've had the same problem with the Galileo site. For some reason, most of the time it won't display late afternoon and evening flight inventory, particularly non-stops. Checking another inventory site, I'm afraid the news is not good for securing a seat in F on AA154 - there are none, zip zero, to be had at this time! The aa.com seat locator also shows all seats in F taken for this flight.
I'll also be flying AA112 in C later in Nov., returning to DFW via ORD and LAX to complete my mileage run, and would be curious to know what you thought of the service, food, etc. on this flight.