New Stroller

So it looks like we're going to have to get a new stroller.  We have to choose between the City Select double stroller or the Joovy Caboose.  I'm leaning towards the Caboose since our son will be close to three when our little girl is born.  He won't want to sit in a stroller anymore.  He doesn't want to sit in his stroller now which should be the selling point right?  I like the Caboose because he'll be able to sit if he wants and also stand.  Hmm, what to do.