I think that having one child, who is a good fit for your daughter, will be wonderful for you. They will play together and you will be able to get all your chores done during the day. Two little ones is certainly manageable to take out to do errands and shopping too.
I have my own two children and two others that I care for and I am able to get most of my chores done during the day. I don't do errands with the four of them but I definitely would if I had just two. Combine it with a stop at the park on the way home and the parents will be happy too.