Stepper Motor - Motor Shield - Power Supply

Hello everyone, I am fairly new to electronics so if you can bear with me I would highly appreciate the help.

I am looking to power a stepper motor from the arduino motor shield and im not sure what kind of power supply I need or even if the motors I have would work with that shield.

Stepper specs:

Holding Torque: 48N.cm Type: Hybrid Phase: 2 Current / Phase: 2.5A Step Angle(degrees): 1.8° http://www.aliexpress.com/store/product/Free-Shipping-NEMA-17HS-5425-stepper-motor-length-48mm-holding-torque-48N-cm/707369_475731728.html

It seems i cannot run this motor from the arduino shield because it requires higher amps per phase than the board can supply. Is there any way around this problem ? Could I just run it with lower amperage? or do i need to get another stepper or driver?

External power: In previous projects I was powering the arduino from a wall adapter rated 1000mA 3-12 V. I assume this is not enough for the stepper, what should I get instead? and how exactly should I power it?

In the final scenario I would like to have a potentiometer controlling the speed of rotation of the stepper, spinning only in one direction.

Get a notebook power (19V 4A)
Problem when using the L298 H-bridge: U get no current control and the motor will get very hot.
!!! use PWM because current will be very high!
(Heat can be reduced if you power only one coil at a time)
To get ‘full control’, use a proper stepper motor controller. (like Pololu A4988)
This will allow you to control current… and use microstepping