Champdogs isn't a bad place to look for litters.
I'm a bit choosy and didn't want a golden retriever that is just a pet without having much showing or working in its pedigree, but I've had goldens for 14 years and am on my third now.
Broadly I would say, you don't want one who has bred from a bitch under 2.5 years or over 7 years. Nor one who's having a first litter at over 4.5 years ideally.
You want mum and dad to have hip scores, elbow scores and an in date annual eye test. I would say you also want mum or dad to have other tests showing they are unaffected for the likes of GR PRA1 and 2. If one is clear the puppies could be carriers but wouldn't be affected.
Decent breeders usually stipulate you can't breed without their permission and some will stipulate their views on neutering and feeding also. I was vetted heavily by the breeder and it gave me a lot of confidence in them.
I'd be skeptical of anyone who owns mum and dad, because it's unusual that you own two golden retrievers who are likely to compliment each other so well in breed standard terms. It doesn't cost that much money to use a nice stud, and often, decent owners of studs will 'vet' the owners and bitch and do not stud their dog out to them if they don't think they are decent.
Personally speaking, when I was looking last year I tried to find a litter by a Xanthos stud (Heather Morss was really kind and gave me a list of people she had recently studded her boys out to, she wasn't planning a litter at the time) as my eldest is by Xanthos Ferrari. This didn't turn anything up for us very quickly and in the end, the puppy I ended up with was by a Messano dog, who are show bred generally but very beautiful dogs albeit on the lighter side colour wise. I'd be reasonably comfortable that Xanthos and Messano dogs are only studded out to reasonably decent breeders. There will be others who are similar.
I just had a look on Champdogs and I can't see a GR litter that impresses me very much,but I am a bit picky. Worth setting up alerts on there and checking them out as they appear. Lots of breeders don't like Xmas puppies either as it's a lot of hassle when people want an Xmas puppy and they have to sift through all that crap to find decent owners. Some breeders have waiting lists long before they breed also, but equally, some people on the list back out, or wants bitch and there are not enough bitches so dogs become available etc.
My pup from last year was only £2k. Not everyone takes the piss £ wise and Heather from Xanthos actually told me that she found out someone was selling puppies by her stud for £4K and she was very unhappy, as there is no way that amount was fair or justified. She even said if I found someone who had used her boys doing that to let her know as it's not on, which I also thought was decent.
Another decent place to enquire is your local golden retriever club. Mine is Eastern Counties Golden Retriever Club, for example.
I am now going to hop off my soapbox and try to go to bed, dreading trying to get a GP appt for a 2YO who has been feverish for five days in the morning.