I'm currently powering the servo's from the Arduino Mega's VIN connector. Although these servos can draw a considerable amount of current they typically don't unless they are under a significant load (which they're not in my project). I'm powering the Mega with a 9 Volt 1 Amp power supply.
It looks like this board will work okay with 3.3V micro-controllers like the Raspberry-Pi as well. The logic IC's only need 2V to operate. So far I've only tested this board with 5V micros.