I wish to use the 8814 in a dual motor robot platform. However, I will be running this at a voltage of 6 VDC for the motors and 5 VDC for the logic. The datasheet states a minimum of 8 VDC for this motor driver. Can I use the lower voltage to drive the motors? I also have two motors drawing up to 2 amps per motor. What size heatsink would you recommend? What would be the minimum component version for use with PWM?