if ur brake pads still have enough friction surface left, just keep them. they'll be fine to use on the new rotors. the noise could be from the pads, but not because their low. theres metal shims on the caliper bracket the hold the brake pads in place. these shims need to be greased to prevent squealing noise. when u replace the rotors, remove the brake pads, clean up the shims with degreaser and a wire brush and put new high-temp grease on them.

 

Whenever I get pads, I get the "quiet" - type. Hawk makes great pads, but I'm not sure about your particular compound. Have you tried having the rotors turned? Warped rotors will cause the brake pedal to pulsate, but uneven pad deposits on the rotors will result in the same thing.

By the way, not all rotors are equal. PowerSlots are cadmium-plated, which is much more durable than cheapo zinc-washed or unplated rotors that will rust quickly. My PowerSlots are 3 years old and only the pad contact surface rusts when I wash the car. That's the only part of the rotor that is not plated - for obvious reasons.