I am due to pick my puppy uo on Wednesday when she is six weeks old. Is this to young and should I wait?

If the breeder is willing to give her to you at 6 weeks then I would not trust them.

A good breeder will not let a puppy go to its new home until it is 8-10 weeks of age.

They learn important social skills in this time from their mother such as bite inhibition (very important)
Breeders who let their pups go any earlier are backyard breeders and usually have either had an accidental litter, are doing it to make money and/or are making "designer dogs"

Shaz, I take it you know a bit about dogs/puppies? Here is a situation/question for you.

We just rescued a pup from our local animal shelter, they CLAIMED this puppy was about 6 weeks old, that the litter of 4 had been brought in 10 days ago having been found abandoned. Now, this pup (which has A lot of lab in him) is TINY, only weighs 3.5 pounds. We're guessing it MAY be about 5 weeks at THIS time, MAYBE. We brought it home and it won't eat, won't drink, and hasn't for 2 days. Carried him to the vet yesterday and they gave him 150cc's of saline via IV because he appeared to be getting dehydrated. He had worms and diarrhea. Vet de-wormed him, gave him something for diarrhea, and now he has no worms, but still has the squirts

The only thing we were able to get him to eat was a mixture of baby strained chicken and plain brown rice. Needless to say, he still has the diarreha, but its solid rice coming out. He barely drinks any water at all. He seems depressed, and skiddish. He'll only play for about 5 minutes after he wakes up, and using the word "play" is being generous. In general, he just doesn't seem happy and only wants to sleep.

We're using a crate to keep him in, but I fear that leaving him in the crate tomorrow (for approx 6-8 hours) when my wife and I both go to work, that all that will do is stress him out more as he just whimpers and cries if one of us is not in sight.

We've had puppies in the past, and have never ran into problems like this, and are really at a loss of what to do or how to fix it. Im not sure who is stressed more, the puppy or my wife and I. :(

Tough situation, firstly let me say thank you for adopting the little tyke.

First thing I would do is grab some Pedialyte from your local chemist /Pharmacy.

Is he drinking water? Or is he still drinking milk?
To encourage him to drink the water and keep him hydrated firstly use the pedialyte, then you can try adding a dash of puppy milk to his water (NOT cows milk)

If he is reluctant to drink then feeding him with a syringe or even a baby bottle might be your best bet until he is in better health.

As for the food, what you are feeding sounds good... Have you thought about trying some puppy dry food?
It is a little more balanced for them.

To encourage him to eat that you just need to soak the dry food (say 1/2 a cup) in 1/4 of a cup of boiling water for half an hour.
It will basically turn to mush and will be easy for puppy to eat.
On top of that he is getting even more hydration from the water it is soaked in.

If the diarreah continues for much longer you will have to take him back to the vet.

Good luck with your puppy, I will keep my fingers crossed for you.

Shaz, yes to ALL of the above, LOL, we've done everything you suggested and none of that's worked. Check out my other thread titled "at a loss for what to do". Its about 3 pages long now.