Because the excitation and emission spectra are fairly broad, these different sets of wavelengths are not substantially different. If it is a question of getting the maximal possible sensitivity, then you should take the spectra on your instrument. Each instrument is slightly different.
The bandwidth (slit) selection will also have a large effect on the sensitivity. Wider slits give greater sensitivity, but also more background. Make sure you subtract the background at each wavelength setting when measuring sensitivity and signal-to-background ratio.