From the registered names, there is nothing to deduce what the bloodlines are....Is the last name of the breeder Weaver by chance???
At the very least, be sure that the parents are OFA certified to be free of hip dysplasia....just because "they run around and look fine" does not mean anything! Do either of the parents have ANY type of training and credentials??? A CD, a CGC, Rally? ANYTHING?
To get the best chance of a healthy stable dog, you should buy a puppy whose parents are proven to have no hip/elbow dysplasia (the OFA Certification) and whose temperament has been tested and judged by someone neutral and qualified. Normally, I would suggest IPO/Schutzhund titled parents, but by the little info given, I doubt they are titled or training for those....at the very very very least, a CD under AKC judges would substantiate that the dogs have decent nerves and trainability as they would have to go to at least 3 shows and qualify with a 170 out of 200 possible points. Dogs are comfortable in their homes, and the owners may never see any issues there, so proving that in a neutral venue is the MINIMUM that you should require of a breeder who is producing a puppy who will be your companion for the next 10-12 years.
Csabre Sch1, Hexe Sch2, SG Bengal, Lynx, Komet, Kira HGH & Kougar v Wolfstraum ~ Ziberia IPO1 ~ ATB Basha, Kougar & Kyra, Fenja, Sch3s, Cito, Sch2, Danger RH & Alice Sch1s ~Kelsey