What most people need to understand is that really good breeders constantly have demand for their dogs, and yes, that means that people are putting down deposits early, and possibly from other litters. Many breeders won't take deposits until the puppies are on the ground, but those that have a constant supply of puppies generally do because they know that if they don't provide you with a puppy this time around, they'll have one in a month or two. If they're a good breeder, they're not at a shortage for customers, so they're not about to hold a puppy for someone that doesn't want to put down a deposit. On top of that, they have no idea who you are, and without a deposit, you can just walk away at 7.5 weeks and the breeder is left scrambling to find a home for a puppy.
In regards to a relationship, and people will probably get mad at this, but unless you're going to be showing/training/trialing the dog, most breeders that focus on those areas are probably not going to really be super excited to develop an extended relationship with you. They just plainly don't have the time. Should they be friendly and available? Absolutely. But if they're producing a lot of puppies, have 30+ buyers a year, they really can't be best friends with everyone.
You should still probably list your location, you'd be amazed at how many breeders are around that don't have websites and you won't find through a google search.