I think there should be things clarified:
In short: there are 3 components needed for control. A motor, a driver, and a power supply.
When you want to use a stepper motor in a project, you need to use a stepper driver. A stepper driver takes in the STEP and DIR(ection) signals to modulate the pulses to the motor. When you are looking at the specifications of the stepper motor, what you need is a stepper driver that can power the current requirements (amperes) of the motor. Once you have a stepper driver that can supply the required current, you then need to find a power supply that can power the stepper driver.
My suspicion is that the power supply you have is okay, but you need to pick out a stepper driver still. This is where I cannot answer, but rather suggest companies that make these sort of things. Circuit Specialists has stepper drivers that would fit your needs as they have high current and high precision. I suggest you do more research as any further answering would be opinionated.