My 14 week old puppy died...but Questions

Ok, so I'm new here. Hello
Unfortunately I have to start my introduction with a sad story... but I need advice.

STORY:
My family adopted a very good and healthy GSP puppy from a reputable breeder. My husband and 4 (very young) kids were so happy! We loved him so much. At 14 weeks he got a mild cough and it slowly got worse... fast forward 1 week, $2000.00 and a hundred tests later what we were hoping was treatable valley fever turned out to be lymphoma. I used to be a vet tech so I helped him as best I could until the diagnosis. Because his progression was too far he had hours to live... we put him down to ease his suffering as he could barely breathe and lost over 5 lbs.

QUESTION:
My breeder has a 24 month health guarantee and a group of puppies ready to go home next week. Honestly it is too soon for me personally (as I'm still very sad) but we chose to get a new puppy because my kids were so sad about their first puppy dying. Also, I would love to share our home with another puppy as our first adored our home. However...
I'm scared to death. I'm scared these puppies aren't healthy, despite a hundred positive reviews. I'm scared we did something wrong. I'm scared the puppy will die. I want to make sure this puppy gets the BEST POSSIBLE care right off the bat... So should I take the new puppy to a vet to get checked asap? Has anyone else has this happen? Any advice I would be happy to have.


❤
RIP beautiful boy. I will miss drinking coffee and cuddling with you every morning. I promise to take care of your little half brother.

You have had really bad luck, and I do understand how you are feeling.
You have been desperately unlucky with the puppy that you have lost, and the odds against it happening again must be greater than those of winning the lottery. If your breeder does the health tests that are recommended for the breed, they are doing all they can to breed healthy puppies, and I really can't see the same random occurrence happening again. I'm sure that you can give another puppy a perfect home, and that he/she can help to heal that puppy sized hole that you have in your heart. You have to feel ready, but when you do, have faith and go for it.