Brushed makes control easy. Can simply switch on and off, and can do speed control using PWM.
Best to look for a logic level MOSFET, as that can be controlled by an Arduino. Should be able to switch well more than 90V, and be able to handle the stall current of the motor (can easily be 3A). So a 5-10A MOSFET able to handle 150V or so would be safe.