You should go with the one from Adafruit, because that one can hold up 8x AA batteries, which will provide you with the adequate voltage of 12V as opposed to 9V from the other one.
This doesn’t mean you won’t be able to power your GoPiGo3 + Raspberry Pi with the battery pack from Robotshop, it just means you won’t have as much range as with the one from the Adafruit.