Re. Raspberry Pi, be sure to get the Pi 2 as it is much more powerful with more ports and only relative peanuts more $$

Pi comes with its own Linux implementation and IDLE which is the Python IDE so with the purchase of a monitor, a keyboard and a USB wifi/Bluetooth dongle you kid has their own computer to learn all manner of skills on.

Another fun item is an Arduino micro controller.

A lot of cool possibilities unfold when you put Python, Pi and Arduino together as well..

Become what you are