Lucky you with a PI shoot!
Here's what we use locally for camera mounts, havnt had one fall off yet and they've wouldve fallen off for sure by now if they ever were going to. Drags, hillclimbs, motokhanas, track days etc - nothing phases it. Doesnt come with a go pro but you buy that separate. Link is http://www.launchhelmetcams.com.au/accessories/gopro-suction-cup