The convertible might have had a *smaller* range of engine options available compared to the sedan, often leaning towards less powerful engines to manage the extra weight of the convertible top mechanism. You might find a particular engine option in a sedan that wasn't offered in the convertible that year.
To know for sure what engines were available for a *specific* 2003 Sebring convertible versus a 2003 Sebring sedan, you'd need to check the original factory specifications or look up the vehicle's VIN to see its exact engine.