My husband did NOT want another dog after my standard poodle died. I wanted five years, then told him, "You know I'm getting another dog, right?" He was not happy. He went with me to pick out the puppy, which was the last one. He liked the puppy because it didn't jump on people. It took a day or two, but he ended up loving Hamish. It took about five minutes for him to start telling me how I was training the puppy all wrong, and another five minutes for him to work on tug with the puppy.
I think you need to let DH know you are intent on showing dogs, and that there is a fantastic puppy available. He'll look sad, but probably come around. He's going to probably agree to the puppy, not because he wants another puppy, but because he wants you to be happy (and happy with him). Remind him that a drinking is more expensive.