Godparents?

Anyone have or will have their baby baptized? I'm trying to decide who to pick for godmothers and having a hard time. I have 2 older sisters and want one to be a god mother for my son and the other for a godmother to our next baby. Thing is, we had such a hard time conceiving I'm scared there won't be a next baby so part of me wants to have both as godmothers for my son. What would you ladies do? Pick just one in hopes there is a baby #2 in the future or pick both in case there isn't?