Hello Martin,
The power requirements are around 500mA @ 5v
Most usb chargers will provide plenty of power if you use the usb jack.
There are no secrets for mounting WVR, I suggest using a protoboard to connect buttons, audio in/out, etc, and drill a hole in that, if none of the components that you use provide mounting capabilities.
Soldering pin headers is probably the most basic of soldering jobs, so don't fear, no special precautions are needed.