The RoboClaw motor controllers from Ion Motion Control (formerly Orion Robotics) can control a pair of brushed DC motors using USB serial, TTL serial, RC, or analog inputs. Integrated dual quadrature decoders make it easy to create a closed-loop speed control system.
Ion Motion Control has replaced the MOSFETS on the RoboClaw 2x5A Motor Controller (V5) with better ones and is now calling it the RoboClaw 2x7A Motor Controller (V5). The 2x7A can supply up to 7.5 A continuous and 15 A peak, up from 5 A and 10 A, and is otherwise functionally and physically identical to the 2x5A.
More details are on the RoboClaw 2x7A Motor Controller (V5) product page.