I went to HomeDepot, and bought a couple of their Orange Buckets.....
Use ziplock bags for your brining, and just toss them in the bucket.
in the summer time, I use ice on top then... but since I am in NEBRASKA, and we havent' been above 30 degrees all winter(gosh I hate that) I just leave them in my garage.
The buckets work great though, and like the other post stated, make sure you just check the ice, and replace when needed!