I am the last person on earth to say anything about getting more dogs...I have 8! While I agree pretty much with the pros and cons, I do want to advocate one point. While Im all for a new pup and I know your family will give him/her a great home, please think about one "person" first. Your old dog. From what you describe, he is very old and not long for this world. Sometimes puppies can be very hard and stressfull on older dogs, either physically or mentally. I'd have a frank talk with your DH and family to discuss wether it might be better to wait until Bailey passes before introducing a new puppy into the house. I'd try to stay as objective as possible for Baileys sake. If you feel that Bailey can adjust and be ok with a new pup, and you can afford it, then go for it. If not then, that is ok to. Me, I would not get a pup until Bailey passed. I think for an older dog like Bailey, it's just too much.
But if you decide to get the pup, I wish much luck and happiness with your new pupster!