Can I use this controller for 5:1 Micro Metal Gearmotor HPCB 12V?
We do not make that product and are not familiar with it, but it seems like it would be okay to use with our Micro Metal Gearmotors based on the specifications.
What would be a similar part from Pololu?
We do not sell any drivers assembled with a direction switch and potentiometer to control the speed like the product you linked to, however; you could use our products to make something like that. For example, you could use a microcontroller board to read a potentiometer and a switch then control a motor through one of our motor drivers. Alternatively, you could configure one of our Simple Motor Controllers to accept analog voltage input from a potentiometer to control your motor’s speed.