Our Micro Metal Gearmotors are probably the closest match to the size of the motor you mentioned. We carry encoders that work with the version of those motors that have extended motor shafts.
It is not clear what type of control you are looking for (e.g. position or speed control). If you are looking for position control using encoders, you might consider the RoboClaw 2x7A Motor Controller. I suggest looking through the user's guide carefully to be sure it is appropriate for your application and you are comfortable using the RoboClaw.
If you want speed control, you might consider using one of the encoder channels as tachometer feedback and using one of our jrk 21v3 motor controllers. You can find out more about the jrk in the Pololu Jrk USB Motor Controller User’s Guide.
Both of those motor controllers have a current sense feature.