So you are looking for a Toller?

 A few things to remember:

Always ask to see the pedigree of both parents, at least the mother's and a copy of the father's. See how much they are related.
Ask for a conformation in writing that the puppies will have an official pedigree.
Look at the age of the parents.
The bitch and the stud dog should be 2 years old.
Make sure the puppies grow up in the house, living with the family. Toller puppies (in fact every puppy) need a lot of socialising, and getting used to house-life.
Keep an eye on the mother, if she is shy or nervous, the puppies will copy that behaviour.
Demand to see the official hip certificates from both parents. Don't let any body fool you. The fact that the grandparents were okay, doesn't automatically mean that the parents are. They have to have official documents to prove that.
Same thing goes for eye tests. Ask to see the official certificates, and also ask about the parents Optigen-pra-dna status.
When buying a puppy ask for the buyers/sellers contract and guaranties IN WRITING.
If, for any reason you don't get to see all this, or some-one doesn't want or can't tell and show you these, just walk away and try to find a real breeder, some-one how cares for the breed and health.

Good luck in your search for a healthy and well-socialised puppy.