First and foremost, are you sure you need a stepper motor? The main benefit of these types of motors is precise positioning. If you just want a high-torque motor without the need for precise positioning you would likely be better off with a regular DC motor.
In either case, you will need a "motor driver" for your motor, as the Arduino cannot provide enough current directly. Sometimes this is called a "motor controller" but I am picky, to me a "controller" is what has the intelligence (Arduino in this case) while a "driver" converts low-voltage/current signals to the higher voltages/currents needed by the motor. Your PhidgetStepper part does both.
: compatible with Arduino UNO, 24V operation, all I/O's fused and protected