I think dog boots depend on the dog, I've only tried them on one dog, and it immediately became her mission to get them off. So for us they didn't work. There are a fair number of people on the board use them with success. Many have also recommended "Musher's Secret". I've never used it, but I plan on picking some up before the snow flies.
No recommendation for a specific bed, but I'd use some that keeps them off the ground and out of the wind. Many years ago when my dogs lived outside in kennels at night, they had raised houses with a pad and blanket. They were fine down into the mid 20'sF, but if it was colder than that I'd bring them in.