Gopro Mount question

I am looking at buying a gopro but with all the different options and a limited budget im a bit confused.

Would I be able to buy the HD hero naked and use the one mount it comes with to mount to my helmet. Does this mount allow you to tilt the camera backwards and forwards so that I can get a good view.

Or will I have to spend more and buy the helmet mounts?

Also anyone know where I can get a good priced second hand one

Yes but the mount will have to go high up on the lid ,you can stick the mount towards the front but not much because even though you can tilt the case forwards and backwards the back of the case hits the mount when fully leant back at about 45 degrees. 8)