Horrible Decision to Make

This morning at 3, I woke up to the sound of a cat squealing, followed by the cockers barking and the baby crying.
Gannon, my big lummox husky, attacked my kitten, Noya. SO ran to the rescue, and stupidly put his hands near the dog's mouth, trying to pry the kitten out. Needless to say, in the excitement, Gan bit him. Such a mess. The poor kitty had to be put down, and SO got stitches in the ER. At first he wanted to get rid of the cats, and then switched his mind - Now he wants to get rid of Gannon. I begged him to sleep on it, we have both been up since the incident and aren't thinking too clearly. It was quite a shock to see this normally gentle giant with such a bloodthirsty look. His previous owner never told us about Gan's hatred for cats until after we'd brought him home and bonded with him.
Something must be done. But I'm not sure whether to get rid of the cats (there's 3 others, including one I've had since she was 5 weeks old) or get rid of the dog. Has anyone reformed a cat-killer dog?