Screw Size----Stepper Size?

Hey evryone....I have been having great feedback, thanks to all. I
have also been looking through the faq page and have been getting
some good info from there. I am starting to look for screws and
steppers now. However, I do not want to make any critical mistakes
and buy the wrong sizes. My table is going to be 10' x 4'. I have
gotten some suggestions on my large screw. I heard it needs to be 10'
x 1.5" and I need at least a size 42 stepper motor to turn it. I want
to connect all these directly, no belts or chains. I heard they dont
last as long and make everything run slower and less precise. For my
y axis I am going to get a 4' x 1" screw but do not know what size
motor. And my z axis alls I know is I probably want a 2' screw but
dont know what diameter or size motor. There will not be much
pressure on the bit as alls I will be cutting is foam. Thanks in
advance for any help.

Mike