Ive got the Helmet Hero set with 2 different helmet straps,adhesive mounts and the other long arm/short arm mounts.Also got the bike handlebar mount thingy and dont think its great for the money.Lots of reports of them breaking.Tends to wobble a bit.
Wiggle sell a cnc'd alu mount-cant remember what its called.
Hint:you can make your own chest mount handy enough with the base of the presentation box it comes in-the black bit.
Just drill a hole in each corner,hook a couple of bungee cords through the diagonally opposite holes,and away you go.Used off roading a few times,worked fine for me after a bit of tweaking.
In fact, the black base could probably be used in a few different ways.
Try http://goprouser.freeforums.org/ for more hints,etc