Well regarding the shader you could paint it in photoshop(or just find a photo of sand), or try to follow that tutorial more carefully.

Have in mind that you should model the sand at least some, a plain shader on that wouldnt look that realistic really(Look on the tutorial page and you see that the sand is not completely flat.

And regarding the coins, at least I havent heard of a easy way to make such an animation, I would recomend that you just make the top layer of coins and have a handfull of coins bounce down in the chest by using keyframes.

Best of luck.