Any good full synthetic is fine. I've run my past few GG's at 100:1 Amsoil saber and the top ends look great.
If your concerned about top end condition, jet correctly, and make sure you let the bike warm up (at LEAST till the fan comes on) before winding it up. I see so many riders start up there bike and rev it to the moon to clean it out. Can you say Cold Seize.....