My kids are 20 months apart, so I needed the double stroller too. I unfortunately really only used mine for about 4 months, I found that a sit and stand would have been a far better option for me, but it sounds like you definitely need two buckle up seats. I have a Graco DuoGlider, and I really like it. The basket is HUGE, and now that they have redesigned it, you can get to it with the back seat reclined, which you couldn't do with the older models. We have a minivan, so space isn't so much an issue with us when you fold it, but I have put it into several rental cars and some friends' trunks too. It fits in the trunk of: Hundai Accent and Elantra, Nissan Altima, Dodge Magnum, Mazda Protege, Ford Escape and Focus. I know it fits in a hundred others, but those are the ones I've put mine in. (Sometimes I had to remove the front tray and canopy, but it's very simple to remove and replace) It also has 2 canopies that cover the kids' heads (the Evenflo stroller has 2 canopies also, but the front seat one is not functional, as it isn't even tall enough to cover an average 1 year old) and removable trays on both seats. I think it's a really nice stroller, and affordable too. I have lots of friends with doubles, and only one I know actually likes hers. And it's a Graco. My friend with the Eddie Bauer one hates it and it's HUGE folded up, and a friend I have who had the Costco one didn't hate hers, but said it wasn't a very good one (average size folded up, but nothing removable on it). My Graco IS starting to squeak a lot, but it's also 2 years old now, and my other, single strollers, are also squeaking, so I don't think it's a design flaw, I think that they just get old and squeaky like everything else. I think the tandem strollers are a better option because, even though they are long and not the easiest things to steer, my sister had a side by side, and it was AWFUL. It didn't fit anywhere, you couldn't take it into aisles at the store and it was really a pain to steer because of the way the handle was. Plus the tandem folds up smaller, I think.
Hope this helps!!