Good man

If you don't know someone personally, the heck with a trial. You can still get screwed that way. Best thing to do is go hunt with the owner and the dog. There is always a slight chance the dog won't hunt the same for you but that is very slight. If the dog doesn't perform for the current owner, there is a good chance it won't perform for you either.
Try to buy dogs only from folks you know, good people tend to stick together. When buying from a "circle" of people, your chances of getting screwed go WAY down as a cheaters name travels fast and sticks with them.