Our Oskar is about 16 months old now, he's a standard smooth Dachshund of European (hunting) bloodlines. His mother's side is northern European and daddy is from Austria. Search "Oskar" in powwow and you can find several posts I made about him.
Depends on what you want for a dog - is he going to be primarily a tracking/hunting dog or 90% a house dog....of course regardless of your plans you have to live with the dog the other 8-9 months of the year when you aren't hunting so pick one you can live with.
Oskar is fantastic FOR US - and gets along very well with his pack (geriatric basset, old rat terrier, and middle aged beagle) and he sleeps in the bed with the wife and I. That said, a hard-core, focused, hunting bloodline Dachshund isn't for everyone....and a breeder that tells you otherwise should be avoided like the plague.
As far as the "nose goes" Oskar found his first deer at 12 weeks old and was doing training tracks of 500 yards with very dilute deer blood (water diluted) aged 24 hours by 4-5 months old. We can't use full strength deer blood on training tracks (I dilute the blood about 1 part blood to 10 parts water) or age less than 24 hours or it is too easy and boring for him. 1 pint of this diluted blood is used for a 500-600 yard training track.
More important than the "nose" is prey drive/focus/prey aggression. Pretty much any dog has the nose to track a wounded deer - that is the easy part - you need a dog with the prey drive, focus, and mental connection with the handler to stick out the really tough tracks. Finding a dog, REGARDLESS OF BREED, with these traits is imperative....and how to do that is the ten-thousand dollar question. That is why the best bet is to go with a breeder of proven blood tracking stock for whichever breed you want.
The training is a real commitment of time and effort - there are some books out there, but its pretty much common sense. Just be sure you are ready for that commitment before jumping into a blood dog.
Our dog has really opened up a new facet of outdoor fun for us. My wife LOVES to track and I'd be in the doghouse if I went on a call without her. This year the toughest find was a 16 hour old track of a very poorly hit deer (low ham hit, opened the abdomen, but didn't cut the intestines, VERY small "modern" type broadhead for a "modern" type bowhunter) of 700 yards in a 100 acre CRP field with weeds/briars/bushes as high as your head. Took some work, but we found the deer and the hunter was REAL happy!
Ryan