That is a nice looking doorbell project!
Using those motors, you don't need direction control, since they have a built-in return spring. You also probably don't need speed control. I expect you will want the actuators to be as quick as possible.
You could use a darlington array to drive the motors: http://adafruit.com/products/970
And control the darlington array from the PWM board. Although, that would be overkill if you are not using the PWM to actually control the speed. Another option would be to drive the darlingtons from a port-expander: http://adafruit.com/products/732
The simplest option would probably be to go with some micro servos using the PWM controller you have.https://www.adafruit.com/products/169https://www.adafruit.com/products/1143