Yeah, we gutted all the a/c and heater stuff from his 800 so were able to use that spot. Don't really need a/c in so.cal with the top off.
As for grounding, the bucket is grounded to the body, but I can understand wanting a better ground as I have done that with my front turn signals on on my Scout II. To ground I would suggest possibly drill a hole in the bucket, use a maybe #8 screw and lock nut with washer, then run a long enough black 16ga wire from the bucket to another #8 screw and lock nut with washer to some place behind the bucket in the wheel well area. It has been awhile since I have looked behind the tail lights of an 800 so not all sure where to drill at. Just find a nice clean rust free, or sand down rust to make your connections.