I've been researching the crap out of this question, but I'm one of those guys who can never get enough information before making a major decision - like buying a dog. Does anyone have a recommendation for a great running dog that's also a great family pet? I'm looking for a dog that can run a marathon with me, handle technical trails and will be safe with my young children. So far I'm looking at German Shorthaired Pointers, Vizslas, Brittanys and Rhodesian Ridgebacks (okay, I really want an RR, but I'm kind of worried about my wife and kids being able to handle it while I'm at work, even though I can bring a dog into my office). THANKS!