Just wondering how you know they are warped? The only way to tell for sure is to use a run-out gauge and measure. There are multiple different brake issues that end up as things you feel in the bars or the brake lever and I'm thinking you are just assuming that the rotors are warped when something else is the real issue.
If your brake lever is "pulsing" it might be pad material that has deposited itself in one spot on the rotor when holding the brake at a stop-light when the rotor & pads are hot. This has happened to me and several friends on a number of occasions and we fix it like this; From highway speed, apply the front brake VERY HARD but not quite to a complete stop. Do it again. Now one more time. At this point the pulsing should be gone (if the rotors are NOT warped.... if they are, you aren't doing any more damage trying this) because you raised the rotor & pad temperature high enough to wipe off the pad deposit. Keep in mind the pulsing will come back the next time you hold the front brake at a standstill when rotors are hot.
Certain pad/rotor combinations are really bad about this condition, others are not. I'm not crazy, this really works.
To help prevent it from happening over and over, I've gotten in the habit of releasing the front brake at 2-3 mph and holding the rear brake with just the left foot down at stops. But of course that is not practical when 2-up and both feet are needed.