I agree that you should strongly consider the input from your breeder... she will likely know how puppy personalities develop. (although things can always change from week to week) It's fantastic that you live near enough that you can visit regularly. This will really help you watch the puppies develop, and will help you recognize what behaviors are a one-time thing, caused by a puppy who is overtired or overstimulated, and what behaviors are part of the puppy's innate personality.
If you want a dog to do agility and other performance work, you might choose the most adventurous pup... for many people, that pup might be too much dog. A pup with a strong personality might work best if he has to integrate into a family that already has several older larger dogs with whom he will have to hold his own. In general, for a "good pet quality" pup, you want to pick a puppy who is temperamentally in the middle of the litter. Not the bossy, dominant one, but not the shy wallflower either. This is especially true if you haven't had a lot of experience raising puppies. The more experienced you are, the easier it will be to curb the dominant behaviors of an alpha pup, or to encourage a shy pup to be more confident and comfortable.
But there are some things that will definitely be more apparent to the breeder, who spends all day every day with the pups than they will be to you, even if you can visit often. For instance, in Kodi's litter, there was one pup who always seemed to be on the bottom of the pecking order, he'd get jumped on by the others, and then be screeching for them to let him up. The Kings pointed out that while it LOOKED like he was the bottom pup in the litter, in actual fact, he was, more often than not, the instigator of these little scuffles. He was a rabble rouser in disguise.<g> Now, how that personality works out as the pup gets older, I have NO idea. (and this wasn't one of the pups I was considering anyway) But it was interesting to watch once it was pointed out to me.
Another thing to look at is how people-oriented a pup is. Of the two in Kodi's litter that I was seriously considering, one was super adventurous, exploring everything, and very bold. He was friendly, for sure, but most of his attention was on exploring his world, less on the people sitting there with him. Kodi, OTOH, although also interested in exploring, would break off playing and exploring to come to us, the moment we attracted his attention. He had incredible eye contact, even at a very young age. He was a bit more cautious than the "explorer" pup, but that eye contact, and his intense desire to work with PEOPLE is what made me fall for him head over heels. I wanted a dog who was bold enough to do agility and obedience work, but really wanted to work with ME.
That's what I got. Kodi lives to work. Not that he doesn't enjoy a good romp, play, tussle or RLH as much as the next dog, but he'll also follow me into the kitchen and look me right in the eye. I'll ask him, "Do you want to do some work?" and he'll come right over and set himself up in heel position. He turns himself inside out trying to figure out what you want him to do. He's a joy to train. BUT as I've mentioned before, I don't think someone who wanted a cute pet to lay on the couch and just "be there" without keeping his mind busy would be as happy with him as I am. If you don't keep him busy, he'll find something to do for himself, and it's unlikely to be something you WANT him to be doing.<g> You have to be clear about what YOU want in a dog (not just a puppy... remember, ALL puppies are cute!!!) before you will know what puppy is right for you.
I think the most important thing to remember is that, assuming that the breeder is breeding good tempered stock in general, none of the personality types I've mentioned are "good" or "bad" they are just different, and will fit in best with a different family.
Karen, Kodi, Pixel and Panda
(ARCHMX Starborn Kodak Moment CGC, NTD, BN, PCD, NA, NAJ, CDX-CCH, RE, RLV, RL1X3, RL2X4, RL3X3...
plus Starborn's Picture Perfect & Nauti Herd Compact Flash RN, CGC, NTD, SN-C, RL1)