Adding Gimbal to Gazebo for erle-copter

I am working on indoor erle-copter gazebo simulation,
Could you help me please about adding gimbal to gazebo for erle-copter ?

Best regards,

Is there a specific Gimbal that you have in mind?

No, I do not have ;
Do you have any suggestions ? Is this important ?
I am a little new to all this ,
I just want to test using simulation