Double: Valco

"I got the single Valco Runabout with the toddler seat add-on for our kids 18-mo apart. It's working great - the big guy likes riding up high and it's more maneuverable in stores and narrow sidewalks than a side by side. "

Double Stroller: Valco

"I have a Valco double and it is great for my twins (who are about 5lbs different in size). The seats are pretty separate so I don't think it would be easy to access the other child, esp. if she /he is reclined. You could also consider a Valco single with toddler seat, although your older child might be bit young for it at first. We are expecting #3 this summer when the twins are 19 months and I am planning on adding the toddler seat to my double. It is a wonderful stroller, easy to push, and Valco customer service can't be beat if you have any issues (the same can't be said for Mountain Buggy, based on what I have heard). However, it would not be a good mall stroller if you do a lot of that. I have used it several times in the mall - it works but if you do that every week it might be a pain. You might also want to look at the Phil and Ted E3 explorer which a lot of folks use for a baby/ toddler."