I'm getting ready to place my first order for parts for my cnc router I have decided to go with a aluminum moving gantrey with about a 24x24 table. I will be using the xylotex stepper system with the 269 oz steppers. What pitch or thread will I need for my acme lead screws. I would like to machine wood, plastic and some aluminum. I would like to use acme stainless lead screws with atleast a 1/2 diamiter on my x ,y axis. I was thinking somthing along the lines of 1/2-8 2 start. And I don't know what to use for the z axis.

Thank you