Noob Needs Step Motor Help

[the0wn4g3]

Hi I'm new here, so please bear with me.
I'm looking to use a step motor to stir a powdery mixture in water in order to keep it from hardening. A step motor seems to be just what I need as it is cheap and has high torque, but I'm having a lot of trouble understanding how to piece together all of the electronics.
I think I need a driver and a micro controller, but I'm not exactly sure how each piece interacts with the motor itself, and why each is needed. I've read a lot of DIY schematics for step motors, but my knowledge of electronics is not enough to understand everything that's going on in the circuits. All the unit will be doing i stirring water, so all I need the motor to do is rotate in 1 direction constantly.
I'm looking to use one of these two motors:
http://www.jameco.com/webapp/wcs/sto...60&keyCode=PDF
http://www.jameco.com/webapp/wcs/sto...75&keyCode=PDF
They are both Bipolar, but I'm not sure why one is almost half the price of the other.
If anyone can help answer these question, or even show my a DIY step motor set up that would cause the motor to rotate constantly, that would a HUGE help!

Thanks.

[student1616]

usually mixing applications need high speed(i guess).problem with steppers is at high speed you loose torque.so its better to go for DC geared motor.simple to control and gives good torque.