Double Stroller

I'm 36 weeks pregnant and looking for a double stroller to accomodate my 19 month old son and a newborn in a carrier.  I'd like the stroller to convert to a Sit-N-Stand when my son is ready, however, I need 2 seats as well.  Also, I'd like the carrier to go in the back of the stroller as opposed to the front.  Anyone have any suggestions?  I've been looking on Babies R Us and all they have are strollers that have the carrier in the front (that's if they are a sit-n-stand).  Thanks for your help.