Well, with the baby coming I would wait until the baby is past walking around well before getting another dog, let them grow up together, I have hunting dogs {weims} and when my kids were babies we were always worried about the dogs getting jealous, then by the time they were crawling around we learned the dogs were not jealous or a threat, it was actually funny to watch the dogs play with the babies when they were crawling, then they started walking and a whole new problem arrised, the dogs would bump into the kids and send them flying into furniture, and since I hates cleaning blood off and touching up the furniture with wood stain{thats a joke}, we had to keep a really close eye on them while the kids were learning to walk...
You are going to be so busy with the baby "stuff' you won't have time to train a pup is the other issue, but it is fun to watch a pup grow up with your kids, they learn to love and respect animals and the dogs become even more ingrained into your family... plus you train them both at the same time, now I let me kids and the dogs out at the same when they have to use the bathroom {thats another joke}....
Friends of my wife have 2 presa canarios and they grew up with their 3 boys and them dogs watch them kids like guardian soldiers, you walk in that yard uninvited and they will sniff and watch you, maybe bark a few times, but you will be able to pet them and not be in danger by any means... BUT you go in that yard while the kids are back there playing, and I think you will leave in a body bag, its like when they are with the kids and the parents aren't around they are on protection duty...