Nick anyone that is not understanding of your situation and decision to keep the pup should not have had the right to get one in the first place. Any true dog lover would put your situation above their own. There are other pups out there for them but none with the same attachment for you.
Sad news.....anyone who doesn't like a chocolate lab probably has no soul. Our old bully is in palliative care, so we're prepared for when the time comes.....losing them both like that is plain fucked.
Jeez, thats shit news. i have had four dogs in my lifetime, and loved them dearly, they are mans best friend for sure. One thing i find is ever time i think of them, i am happy, as they bring back intense and very happy memories, that will be with you and your wife for many years. I hope your pain gets easier with time, and if you decide to keep a pup, it will fill your hearts with joy.