What a wonderful idea, I'm sure it will bring him much comfort. I agree with others, use what colors you like and he will most certainly enjoy them. Look at JoAnn's for Blizzard fleece. It's heavier and warmer and you won't need batting. If you want it extra warm, you can put a layer of flannel inside the quilt. Be sure to shrink it first. So thoughtful of you to want to do this for him. I like your idea of making a pillowcase finish too. It will be lovely and loved.