Anyone know if such a thing exists?
yeah check out greenlight surf supply. they have what you are looking for i believe.
Not sure about sanding pad to drill, there are sanding pads that can be attached to a drill but they really arn’t very good for doing surfboards, if you can’t afford or don’t want to shell out for a propper sander/polisher then I would recomend a cheap random orbital sander.
Sure - That’s how I did it for a long time… I liked the variable speed aspect.