I'd take Christian Gonzalez. I actually have Witherspoon as the CB1 in this draft, but Gonzalez is right there with him. And I think Gonzalez is a better fit. I think he's the perfect Cover2/3 zone corner. He's just a smooth mover who has developing ball skills and beautiful transitions breaking on the ball. He's not super physical, but has the size to play press man as well. I also think he's a better all around athlete than Witherspoon.
Witherspoon does have inside/outside versatility, but I think he's a guy you want in man coverage. He plays at 1 speed and is 100mph at all times, which isn't a bad thing, but it's also not a very zone friendly style of play.