Owlbait - is the Michigan dog one of the ones that shows up at the Compton shoot?
Selfbow - Oskar is a standard (20 lb) smooth hair. I think the European standard dogs are probably on average a bit smaller than the US bloodlines. According to the FCI standard about 20 lbs is all the bigger a standard should be - US dachshunds - I mean "AKC show stock" not dogs of European bloodlines bred in the US - seem to run bigger, and I don't think you would consider most of them "hunting dogs".
As to picking a dachshund to use for hunting or blood tracking you can't go far wrong if you stick to European bloodlines - they are used for hunting much more than over here. In the US that most likely means standard wirehair (several breeders) or standard smooth (a couple of breeders). As far as a specific pup - I would be sure that the breeder is "doggy" enough to be able to match the pup with your needs - the Volhard puppy aptitude test is a good starting point to assess the pup's personality. For blood tracking you want some serious prey drive and focus. Of course look at the parents of the pup - are they REALLY hunting dogs. I think any dachshund has the brains (they are unbelievably smart dogs, in general), and most have the nose. The other aspects of the pup's personality should be such to meet your wants/needs for the other 10 months out of the year when you need to live with the dog. Oskar has VERY strong prey drive, that is what our breeder prioritizes - along with very good personality, brains, focus/determination, and some biddabilty. He's a pleasure to have around the house, but at 3 yrs old wants to play ALOT - and snuggle. He does not have the biddabilty to be left off of the leash much outside where we live (near a highway) as he would definitely go after the yard rabbits and be hit on the road, this is one compromise we have to make for the strong hunting instinct. I think, in general, dachshunds as they are hounds, do not have near the biddabiltiy of the pointer type dogs....also may in general have a bit more prey drive and focus when it comes to "boring" tasks like blood tracking than a bird dog or terrier. I would also be sure that the breeder has at least some experience with blood tracking or can give you a reference or two - hopefully someone willing to spend the time to help you get started. Some breeders of "blood tracking dogs" unfortunately lack either the tracking experience or willingness to help out puppy buyers getting started.
Feel free to drop me a PM if you get seriously interested and we can talk. We are certainly no experts on this, but we are learning!
Ryan