Why bring them? The whistle you need in case you get lost. You just blow it three times and if someone hears it, they will come to help. The money is for a pay phone. If you bring a cell phone, you still need to bring money because cell phones don't work in some areas.

What kind should I get? Just bring a little whistle that you can buy at most stores. You don't need a storm whistle that will wake your neighbors over in China up, just any little whistle. You also need to bring enough money to make several calls.