You could use the Fisher Price motors, but you probably need to make a gearbox to reduce the speed, but not reduce it as much as the black plastic gearbox does.
We made a gearbox for that motor using a gear out of the black plastic gearbox. It has 4.5:1 reduction. The plastic gear has a hex shaped hole in it, so you can use a hex rod to make a shaft to drive the shooter roller. It might be difficult to make the holes in the correct location, but you might want to give it a try and see if you can do it. This gear reduction should work good with a shooter wheel that is about 5 inches diameter.
