Best way to manually speed control a stepper?

So I have this foot pedal with a pot in it and it works great... I can map values between 0 and 900 generally ... and what I want to do is use a stepper motor that I can control with my foot to go either slow or fast in one direction ... and fast is a relative term... if its 2 revolutions per second than so be it ... I want it to fast as it is capable ... but whatever that speed is ... is fine with me.

I have these motor controllers:

1) Adafruit Motor Shield V2 2) L298N based module 3) DRV8825

I am using a 4 wire two phase stepper motor by the way.

I've messed around with all three, but I've not really been able to achieve the results I want ... when I push the pedal down, I want it to start moving faster and faster the more I push the pedal. When I release the pedal it needs to stop RIGHT NOW....

Anyone know what my best option is for this and if it is to use one of the drivers that I have now, which commands in the library will yield the results I'm looking for?

Thanks,

Mike

AccelStepper library, use runSpeed() in loop(), change speed with setSpeed(), stop with stop()?