Stepper motor speeds

Guys,
I have a pretty good handle on sizing stepper motors with respect
to required torque, but I haven't heard any discussions about speed
ranges and how they're controlled. I'm in the preliminary stages of
designing a CNC retrofit for my Enco full size mill, and would like
to use the smallest motor possible, to motorize the fine feed on the
quill. My down feed requires almost no torque, but retracting
requires about 120 to 150 oz/ins. I have enough room to gear the
motor to feed at 1:1, 2:1, or 3:1, but I don't know the RPM range I
can expect from the motor. Help please!!

Marv Frankel
Los Angeles