If you are going to go with a watering system like this one, I would recomend going with just the poultry nipples in the bottom of a 3 or 5 gallon bucket. The reason I say that is because the PVC pipe that the waterer is attached to WILL freeze in our climate unless you are going to keep it in the coop and not the run. And even then it may freeze. I am just trying to head you off from a bad situation down the road. At least with the nipple in the bottom of the bucket design, you can put a birdbath heater in it to keep it from freezing solid.
Ditto. Any bottle neck is prone to freezing.