That's a tough question. Which one would kill faster? I know it would be nice for him to suffer before dying, but I wouldn't want to risk his surviving. I would sure hate for him to survive a burn unit only to be in a position to propagandize against the US.
The answer I have in mind today, of course, is to shoot Ramsey twice to be sure he is dead. But, of course, this would be a real difficult decision in real life.
(Actually, I think I would release Saddam and Kim, shoot Ramsey once and go looking for Al Sharpton!)
That would have to be one hell of a burn unit to be able to patch up a WP wound.