We started out with a Graco 'travel' system with DD. I really like having the "bucket'. I know a lot of people hate them but I think they have there place and purpose. Not all newborns like slings and pouches. DD only really liked one carrier and that was still only good for a short time. She was happy to be in the stroller. And you NEVER wake a sleeping newborn, having that removeable bucket is really nice. Gives you a place to put the newborn when you do in and eat someplace too.
I liked the Graco but it isn't as maneavourable and is heavier than some of the other strollers we've tried out since then. We now have 2 Peg Perego strollers. David has one (for DD when we are out a long time) and I have one (for DS who loves his stroller, feet are happily bouncing constantly). David's stroller is a Pliko (which is an "umbrella" style one) it's nice and light and fairly compacted. Mine is a Venezia, its a little bit heavier but still lighter than the Graco. I like that it is reversible, I can have Jack face me and it does fully recline into a bassinet style which is nice for newborns. Both have the toddler/small child step on the back so DD can easily stand on it when she's tired and we only have one stroller with us.
I tried the double strollers but they are so hard to navigate. They are like a HUGE land barge.
Especially since you want to have the infant in the back (near you) you have a heavier toddler in the front which throws the balance off. I've tried the Graco Duo-glider and the Inglesina Biposto twin strollers. Definitely liked the Inglesina better than the Graco. After having the Inglesina for a while, I decided we should go with 2 strollers. It actually makes shopping as a family easier for us. We each have a child and can each get around quickly. And we can split up if we want to and no one is left trying to keep up with both kids. Of course that will change with Radish's appearance. :LOL
I'm going get the Peg Perego infant seat to go with one of the strollers. We have 2 Britax RAs for Tori and Jack right now. We are going to move Tori up to a Marathon or Wizard (David is really leaning toward the Wizard because of the head restaint system) and I'm ordering new covers for the RAs. After using the bucket Radish will go into one of the RAs. Ours have held up really well. I like how easily the Britax covers come off and can be washed. Ours have washed up great. We have the Sandstone with is kind of a velvet plush, and it has gotten 'worn' in a couple spots especially where Tori climbs over into her seat (my little dirty monkey :LOL). I plan on replacing the covers with the Jefferson which is a corduroy material. Much more rugged and durable.
We have a Kelty jogging stroller. David is a runner (I am SOOO not! :LOL) but he's only used it a couple of times. It's a really nice one but I've hated using it the couple of times we tried with DD (just out and about at the park and such). I hate that the front wheel is locked, it really makes it hard to turn at least at a walk speed. I can see *why* it needs to be locked while running but it hurt my back trying to navigate it around at a walk. I need to put it up on eBay, it's just hanging out in the attic right now. :LOL
ETA: Oh DS hated the sling (and I tried a bunch of different ones, I have at least 10+ different carrier/sling/pouches) until he was about 4 months old, then he loved it. So he was happiest being held against my shoulder or in his bucket/stroller.