bos1714:
With that said, you will have to have some sort of interface circuitry that will take the signal from the Uno and use that to control how fast the motor will turn. Something like a MOSFET or a prebiased BJT would be great for controlling how much current the motor will take, and subsequently how fast it will turn.Overall, I would recommend using a external battery power the motors, and using the transistors I mentioned.
Do you have any external battery power to recommend? Is this something lithium ion battery pack could be capable of?