What does a guarantee do for you anyway? Most likely, you just get a replacement puppy if yours has HD. By then you're probably so attached to that puppy that you're not going to even want another puppy because you'll have your hands full with your current one. It's not like the breeder is going to reimburse you for a hip surgery or anything like that.
My advice is to go with a good breeder that knows what they're doing, that health tests their breeding stock, and knows what their dogs produce. Just take all the precautions from there once you have the puppy and hope for the best. That's all you really can do when it comes to something like HD as a puppy buyer.
Ever see the movie Tommy Boy? As crazy as he is in that movie, he makes a pretty good point about what a guarantee is. Kind of relates to breeding too.