the reason your barkes are pulsating, they are warped, aka too much run-out
both the hub bearing assembly, and rotor will have run-out
find a shop that has an on-car brake lathe system, just call and ask
they can turn (resurface) your rotors that will correct both bearing assembly and rotor run-out,
if you simply toss on a new set of rotors, it will still have run-out, you will only gain a short time before you feel the pulsing brakes again
you can purchase new rotors, but you still need to have them turned on the car so they match your hub assembly, and all run-out removed, mark each rotor and a stud with a paint marker, so if you ever remove a rotor to do work, you will want to reinstall the rotor exactly where it was...
hope this helps