For the 737-300s used on these routes, there are video screens in the aisle every four or five rows, but they generally only use them for safety videos on two hour flights. Also, on these aircraft on these flights, they generally do not use the audio system either. In economy class, you will get a small snack.
One bit of advice on seating. In economy in the 737-300s there is one row that does not have windows. [I believe it is the 11th or 12th row, but I'm not sure. Best to check with reservations or the gate agents.] It's the row that is next to the main compressor blades of the jet engines. If you like to look out at the scenery below (thats the best entertainment for me), make sure you are not assigned to that row.