So much has been already said, I don't think I want to join this fight.
I don't know if kaiten is stronger or chidori or the other way.
But i seem to recall that Kakashi said that Sasuke can't beat Neji.
Although that was at the time of the preliminary fights is still think Neji would wipe the floor with Sasuke.
So in that sense I would say that Kaiten is stronger than Chidori. And secondly Kaiten is a bloodline limit of a kind and Chidori isn't, that in itself of course doesn't necessarily say anything but it still gives us something.

And since kaiten is spinning at high speed and is chakra, it would probably change Chidori's speed and direction, making it miss. And then.... hell to Sasuke.