Do you think its better to get a pit now or....?

Here's the scenario; my bf's pit bull (8 years old) was just killed on mothers day. ;( well; my daughter is 5 years old and she's at that age where she's really taking on responsibility for the animals that we have as far as ensuring they have fresh food and water on a daily basis. She really misses the dog as do I. He was very well mannered and trained (other than he ran off.) With my bf's and mine school schedule and work schedule if we were to get a pup within the next 3 weeks there would be one of us there most the day to care for the dogs potty training needs and begining discipline. I don't want to hold off past this summer because if we where to get one now; it would be coming into our lives while my daughter is still young and a little rambunctious and would more than likely be 4+ by time we have a second child. (i'm thinking it would be better for the dog to adjust to the baby at an older age and being rased with a young rambunctious, overly affectionate child....