Are you sure the letters aren't "PM" rather than "PWM"? PWM usually means "pulse-width modulated" and I'm not sure why a motor would be so labeled, since any DC motor can be driven with PWM. PM is a "permanent magnet" motor, which is common for small DC motors.
VR is "variable reluctance" and doesn't usually have magnets. It's generally cheaper and has higher torque/lower speed capabilities compared with a PM motor. The speed of a DC motor depends on how much voltage you apply to it and how much load it is driving. It won't be a constant rated speed like an AC motor. Horsepower is pretty much horsepower, but pay attention to the no-load speed and peak torque ratings.
Don Kansas City