Your thoughts on breeder?? what do you look for in your breeder?

I'm more of a rescue person myself, but if this guy does health and tempermant checks, let you meet the dogs and see them work, answered your questions and has a waiting list, he sounds like a reputable breeder. The only other thing you could do is ask him if he would be willing to let you get in contact with anyone who has bought one of his puppies. Some won't simply because they don't give out any contact information of buyers, but others will and you could hear about their experiences and judge from there.