The stalled current is going to be the resistance, nothing more. This is not really relevant though. You will probably want to use some sort of current limiting in case the motor gets jammed rather than leaving full battery voltage across a stuck motor.
The motor has a rated power level. It can usually be used to produce more. What you need to know is how much current it will need for your app, which varies based on incline, weight, tire type, surface (carpet is slow for example), and of course how fast you want to run it.
There's also a point where your tires will slip. Using more current than the tires could possibly use without slipping on the best of surfaces would only happen if an object had jammed the tire or something wrapped around the drive shaft. Those are things you want to shut down for, rather than building a driver that could keep providing it.