For what reason?
I don't rate either very much, but I do think that Best would suit Cisse a hell of a lot better than Bent.
I rate Cisse far, far higher than the two of the others put together, and IMO we should build our attacking side of our game around Cisse and Ben Arfa. I've said it before, but a manager who fails to get someone like Cisse to score is doing something wrong, and signing Bent wouldn't do anything to right that wrong.
I'm also shit scared of Pardew playing Bent over Cisse, either leaving Cisse on the bench or playing him out wide again, which we all know is absolutely mental.