How much does the man really like his SR80's? I wouldn't go into suggesting Grado and Alessandro's left and right before we know he absolutely adores that type of sound sig. Perhaps he should experiment? Definitely and AKG could make those genres sing. I'd say an old K501 or something would be easy enough to grab hold of a pair, cheap enough to try out and decent enough to keep.
Classic rock is much more than modern day rock. Grado's, I feel, are for people who want to here crazy, face-melting guitar solos and feel that kick drum blow air through their hair. But for such a vocal-centric genre that can at times walk that line of utter delicacy, a headphone with a little more soul, as well as timidness might fare better.
If the AKG does it for you, go with an Xtreme K1000 with an Xtreme amplifier to give them bass beyond belief.