Sprey about how late my reply is. The info you pointed out here is so helpful. I was concerned that a dog that was too "high drive" like you see in IPO would be too impatient wanting action that the methods of nose work would not fit (I was told this). It's great to hear from someone who has done nose work. In my head I was thinking about cadaver work or personal tracking. I was hoping one day I could be part of volunteer search efforts when people go missing in the wilderness, etc.
If you are SERIOUSLY considering something like search and rescue work, please be in contact with a local SAR organization well before you ever plan on getting a dog. Most SAR groups have you train with them as a non-dog handler long before you'd be accepted as a dog-handler first...SAR work is very hard. I have a few friends that do it, and a lot of people love the idea (me included!) but really don't have the chops to do it (me included!). It's a hard, hard, hard job. Most of them want to make sure you really have what it takes before you search out the right dog to get...and you need to be prepared for the possibility that your dog might "wash out", too....nosework "the sport" is different than doing search and rescue work (either live find, cadaver work, or any facet of it.
Maybe you're already involved and I'm telling you what you already know, but if you're not in that world yet...get involved in the world before you specifically get a dog for it. Or, dip your toe into the sport world to see if you even enjoy scentwork, and plan for the future later.
If you haven't read "What the Dog Knows" it's an absolutely fantastic introduction to the world of cadaver dogs and training them, the world of scenting dogs, etc. Keep in mind, too, that in some areas of the country Dobes just aren't well suited to this type of work. With their short coat and no undercoat, the weather conditions are going to be a huge factor being able to do the type of work you're asking. There certainly ARE great Dobermans doing it, they are just somewhat rare. If you're looking for that type of dog you'd almost certainly be looking for more of a working line dog, IMO. But, again, please know what you're getting into.
Edited to add - working with narcotics would also be highly regulated...you can't just start training your dog to find illegal narcotics. My area has a lot of judges in our sport that are in law enforcement. We'd certainly be in a ton of trouble if we trained our dogs on narcotics!!!
Sorry - one more edit....pretty much any dog can do the sport of Nosework. Mixed breeds, old dogs, show lines, working lines, many different breeds....if you want to do the sport, look for a dog (or puppy) that is confident, food motivated, and enjoys working with you. You'll be just fine.