stepper choice for woodworking power feeder

I"m looking to drive a power feeder -a typical woodworking power feeder. An 18 volt brushless motor cordless drill works just about perfectly, except that the switch (trigger) is awkward to lock into a speed, and the battery needs to be kept charged. So I'm looking for an option with easier speed control (dial) and that can run continuously off AC powered dc power supply . Steppers seem like a good option. I need good torque at output speed at the stepper shaft of about 3-40 RPMs. Should I be getting a gear reduced stepper for this? Any guess how big a (ounce inch) stepper? The drill works great, so replicating that torque in the speed range I need will certainly do the trick.Thanks!
the project:
Little Proteus Power Feeder
best, Al

Hi Al - I'd measure the torque of the drill using a disc and weight (or scale) then the stepper selection will be easy. You can also look at DC motors with a speed control. Probably a geared one. Maybe cheaper then a stepper. Also a geared stepper will run at that low speed with lots of torque. But we need an actual torque figure to proceed.

cheers Peter