They key to stopping Duke is more about stopping Williams than it is Redick, in my opinion. LSU has the potential to do that. Not saying they will, but they definetely have the potential too.
As for who the best in the country -- when they play their best, UConn is. That seems to be the general concensus among those who cover the game. They're arguable the most talented and they're, with out a doubt, the deepest. The issue is focus, really. They're tall, athletic, talented -- but they don't always show up, ya know?