[yash101]

Use Brushless motors. With the controller, they MAY cost a little more, but will be around the same price range. At those high RPMs, brushed motors are going to rip their brushes off! It will be easier to control brushless motors, as compared to brushed motors because brushed motors don't react to signals linearly, so the small irregularities in the motor will cause them to react differently. With brushless motors, you get absolute control because these motors are commutated by you, so you can possibly set the exact RPM you want! In other cases, you could use an encoder on the brushed motor. However, that would still be quite hard to program correctly, especially on the Arduino. The amount of data coming in from the encoders could be so much that it could overwhelm the DSP!