(I don't know too much about electronics, so correct me if i'm wrong). But the sainsmart motor controller states that it gives each motor .6A, while these motor's stall torque is rated for 4.8A. This would mean that the motors would never get enough power to use even half of the motor's strength. I recently found this motor controller: Pololu Dual MC33926 Motor Driver Shield for Arduino.
The pololu motor controller seems like it can do the job, but I'm honestly not that knowledgeable in the specifics of electronics. Any other suggestions or recommendations would be appreciated.
"Its dual MC33926 motor drivers operate from 5 to 28 V and can deliver a continuous 3 A per motor."
Still not good enough for a stall current of 4.8 A. I'd look for a driver capable of a continuous 5 A or more. You don't want the motor burning out your driver board.
Can you give me a quick explanation of how the current works? I'm still pretty confused as to how it works. Does a motor draw only the current it needs, or can having 10A damage the motor?
Would the one I just linked work properly? Are there any cheaper alternatives that won't compromise quality and effectiveness? This one seems over powered for what I need.
The motor only draws as much current as it needs. The more load it is under the more current it will draw, up to the point where you stop the motor completely where it draws the most current -- its stall current.
"Having 10A available" does not mean it will ever draw 10A, just as when you screw in a light bulb it never takes down the local power plant. The internal resistance of the motor, created from incredibly long windings of thin wire, limits how much current it will take.
I'd respectfully disagree with johnwasser on the MC33926 board. The docs state that the chips are rated 5A continuous if you add heatsinks or other cooling. It also has thermal shutdown to prevent it from overheating. If you're just running around on smooth/flat surfaces I wouldn't expect any issue.