CNC Converting Questions

Hello all,

I am a new to the process of converting machines to CNC, but am very
interested in learning as much as possible before I spend any money.

I have read through a good part of this list and find a lot of this
information educational, but overwhelming. I have not been able to get
a firm grasp of how some of you determined the proper motor size for
you conversions. Many of you, having the same mill (or similar) using
different sized motors. Who is correct? Maybe all of them work, but
what is the best way to calculate the proper size to be sure that the
motor is not over stressed or under driven? With so many factors,
where to start? Then on top of that, you have driver selection and
servos or stepper. Can somebody please help me in figuring out these
numbers?

Machine to convert: MicroMark Mini-Mill

How would you calculate the in-oz needed to hold, turn or turn to lead
screw under load?

What is the best way to control these motors, Gecko or Rutted? Maybe
some other?

How about motor, server or stepper?

I know this message packs a punch, but any help will work:)

Thanks

--Larry