We are planning to go to the zoo out there in a couple of weeks. My main question is...What should we plan stroller-wise? I have a Sit-n-Stand, or a Graco Quattro Single, or a single umbrella. Is it a lot of walking? Are there hills? Basically Chelsea will want to be getting up a lot if she is riding, but I know she won't want to walk a lot and DH will end up having to carry her. Molly will definitely be in the stroller most of the day. I am considering trying to find a double umbrella before then b/c the Sit-n-Stand is pretty heavy. So any info or suggestions you ladies have would be greatly appreciated! Thanks!!!