If you are looking to resurface the rotors check in your area for an engine rebuilder with a flywheel grinder. Grinding has several advantages over turning.
Unlike turning which suffers when it encounters hard spots, grinding produces a level surface. It also allows you to creep up on the material removal stopping just as you get clean up..... maintaining maximum thickness. No risk for chatter and best of all, instead of radial grooves left by turning you end up with a bidirectional pattern which helps bed the pads.