Is this the breeder?
If the two dogs names listed in your first post on that thread are the parents, neither of them are listed on the OFA website. Did you ask for proof of OFA or did the breeder just tell you that they were OFAed? If you plan to breed him I would definitely want PROOF that OFA's were indeed done and research the parents, their puppies and the parents litter mates. If he is the ONLY one that gets cleared by OFA there is not much information to go on.
If the parents did not work how will you what characteristics you might need to improve on or maintain? Would you base it solely on the titles that you are aiming to obtain with him? He is only a SMALL part of the big picture. Knowing the working ability and temperament of his parents and sibling and his parents sibling provides just an much information if not MORE than what you see working with your dog.
With all due respect taking the word of the breeder regarding OFA, health and temperament is not exactly an unbiased view like you would receive from a trial judges and OFA certified vets viewing and grading the x-rays. A local vet is not necessarily knowledgeable enough to read x-rays other than the OBVIOUS routine things the vet deals with. I have some very good vets but I know they do not have the experience to read joint x-rays like the ones at OFA do.
What happens if your dog DOES achieve all of his titles and health certs but say 2 litter mates were PTS because of poor joints or other major health issues and another because of poor temperament/nerve that attacked the neighbor? What are the chances that the breeder would be forthright and share this information with you or even of the owners of the pups would notify them of the issues?
Why would you require that the owner of the female have spay/neuter contracts? What if his pups (should all of the criteria be met and you have proven facts that they other dogs in the immediate family are healthy in mind and body yadda yadda yadda). What if a future puppy owner has the same goals as you do but they would have to spay/neuter their pet?
Personally if I was looking to breed a dog and I wanted to take a crap shoot with a puppy (that may or may not pan out in 2-4 years and prove to be breeding quality) instead of buying an adult (tested, trialed and meets my criteria), I would buy a puppy from a breeder that was involved in the activities that *I* would pursue, I would know they type of personality, drive, work ability and health that *I* want to produce and I would be willing to wait for that perfect pup to be bred, whelped and matched with *MY* goals, abilities and preference.
I would not base the future of my breeding program on the word of the owners of the puppies who, in reality, are looking to make a sale. *I* would not base it on a local vet. Now if it was a well known and respected vet in the vet community it would bring a little more bearing in my decision but I would still want documentation not hearsay. *I* would want tangible proof to back up the claims.
There is a lot more to breeding a dog than just taking ONE dog into consideration.