Mechanical Movement

Motors:
Choice was between stepper motors and DC servo motors; I decided stepper motors would be easier to control. I ordered 3 stepper motors from AliExpress: link

I decided to use belts for converting rotational movement of the steppers to translational movement. They are faster, low noise, and cheaper than lead-screw used generally for this purpose. I found a nice site selling belts, gears and all kind of useful stuff: http://www.robotdigg.com/