I realize I'm a little late to the party on this one, but 11-12 years ago I trained a little bit with a guy that had Wachtelhunds. He had to jump through a pile of hoops to get his dogs and at the time he was pushing to get the breed established/recognized. I didn't get a ton of exposure to his dogs, but they seemed okay and had good temperaments. Haven't spoken to him in years, but it appears he now breeds and has a kennel (Oak Ridge).
While eating lunch in a small diner in NW NoDak in 2011 I had an orange hat on when a guy sat down beside our table and asked how the bird numbers had been. Turned out he was on his way back to Wisconsin from Montana. I told him I had married a cheesehead so we struck up a conversation. I asked what kind of dogs he had and he told me it was a breed I'd never heard of- Wachtelhunds. I smoothly said, "Yeah, those pesky little German spaniels." The dude did a double take and looked at me sideways. Turns out he knew Dave as well and he had been breeding them for a while (Eagle River kennels). He had a female that seemed a bit grouchy, but the rest of his dogs appeared to be tired and happy.
There aren't many of them out there. Looks like there are six breeders listed for the US, so it's pretty funny I've randomly bumped into two of them. The old adage with dogs is there is more variation between dogs of the same breed as there is between breeds. The VDD/VDK German system (or "dog cult" as some friends call it) requires a blood tracking component in their tests. One of my best friends had a great VDD dog who was money on grouse, pheasant, ducks, deer tracking, and quietly cuddled with their young daughter at the end of the day. Unfortunately, she died this winter at the age of 12. Like any breed, proper exposure during the puppy months can prevent a lifetime of dog "issues with kids."
I've seen firsthand how much more emphasis the Europeans put on tracking/retrieving versus breeders in the US. My dog's mother was an import, and I would stack my old red vizsla up against anybody when it comes to finding a crippled bird or a deer. He'll be 14 in June (good Lord willin'!!), but his desire to track and retrieve was something he showed naturally from a very young age. I dread the day I have to look for another puppy.
Best of luck in your search and spend some time talking to as many people as possible. I had dozens of people tell me I shouldn't get a vizsla, because "they don't hunt- just get a GSP/Brit/Griff/Lab/etc…" If you haven't already, check out a local NAVHDA event and talk to some folks. I found the best blood I could get, and could not have found a better dog for my needs. I'd never owned or trained a dog before, but we managed to bumble our way through a Prize 1 Utility Test on our first attempt. I had no real desire to test him at that level, but since most of it came naturally for him we did it.
When you do find a new pup, take lots of pics and post a few!