SureFire white light, EOtech...
For a protection 12ga, I'd buy a SureFire whitelight fore-end or add a laser-aimer/light if the weapon has any 1913 rails.
The EO holotech line of milspec red dot sights.
As many LE officials & security experts state, use of force incidents take place in low light. Aiming may not be needed with a "room broom" in a CQB event but a bright light may prevent mistakes/ADs.