Replying to SLVSH GoPro Setup

I want to improve my follow cam setup a bit. We have a hero 6 and a hero 8 and one gimbal. I haven't really used the hero 8 with the gimbal yet but do you think the gimbal is even necessary with hypersmooth? My main question is how to add a mic to this. I have never used a mic in the past but I find that the sound of a landing or rail really makes edits way better. What mic should I get and how do I set it up? Also I have the feiyu g6 gimbal. I think I could attach a mic to this but is it possible to use a mic without a gimbal or no?