Struggling to decide what to do stroller wise when the baby is born.

I am having baby #3. I have twin 4 years and my stepdaughter will be 2 by the time the baby is born. I dont know if I should do a double stroller or a single travel system and an umbrella stroller. We only have the girl every other week. my 4 year olds are getting too heavy to push in a stroller and so is the stepdaughter. She weights as much as my boys. So what should I do? A double stroller or a travel system? Because I will have a baby wrap so if I do have to venture out without my husband I can alway pet her in the stroller and carry the baby. The boys can walk since they dont sit still in a stroller. Opinions?