Regular ones that cost about 20-25 bucks. I did not see the benefit in paying more to be able to pan and tilt. Could be useful for the run, but the coop would never need it.
I also bought a pair of the "outdoor" housings for them. They are not official since the cameras are not meant to be outside, but you can see on Amazon that many sellers sell housings for the camera so that they are somewhat protected from rain/dust/etc... They are not going to be perfect, still lots of ways for water to get in. But it is better than just slapping the bare camera up on a fence post.