In my experience, 1000 fps is not enough to routinely dispatch those vile ring-tailed demons with a body shot. I got lucky once, but that was a hit on the varmint's exposed underbelly (12 yards, Air Arms ProSport, .177 Beeman Crow Magnum pellet). I was actually surprised that he croaked. Judging from the entry site, I'd say that the round probably penetrated enough to put a hole in the aorta. Hits on the chest or flank have just annoyed them.
Other hits where I've had some success: nasal bridge, where the nose joins the skull; skull just above the eye socket; side of head just under the ear.
So, my personal opinion is that 1000 fps can get the job done, but shot placement is the key factor.