ISO lightweight stroller for twins

My twins are almost a year (sniff sniff) and are close to the dreaded switchover to convertible car seats, which will render my double snap n go useless. I'm looking for a lightweight stroller to run errands with, possibly go to the mall with. I have a big baby jogger double (an older version of the baby jogger gt double) for neighborhood walks and longer outings. I would like something that's easy to get in and out of the back of my van and that I can steer one handed.