I choose to listen to metal through Beyer DT770 Pro/80s because I like the heavy bass that the can offers for that genre. But I listened to metal for 2-3 years with SR-60s before this and was plenty happy.
Since you already have MS-Pro I suspect you have a pretty good idea of what the MS-1 sounds like. You could even use the same pads and have almost the same feel so there would be no sonic or physical shock there....uh, the headband would be a "little" shock. So that one is almost a no-brainer if it's the right sound for sure.
And from my understanding, the Grados are about the same with a bit more "fun" tossed in!
One nice thing about the SR-80 over the SR-60 is that you can also get it with the 1/8" plug which is easy on the iPod and the four conductor cable, and with the bowls you probably are already comfortable with.