L.Z.
Hi H. - I don't know anyone selling theirs, but I just wanted to tell you that I have exactly the one you describe, and my girls are the same amount of months apart as your two will be! I love the stroller and it's great for both kids. My kids are in it all the time, and they are now 3 and 17 months old. If you can't find anyone selling, I encourage you to buy it if you can budget for it because you will use it a lot if you are active and out and about. They make a bar now that fits over the top so you can put any carseat on it too while the baby is in the infant/carseat stage.
I hope you find what you are looking for! You still have time to look, so you never know. Keep searching! Good luck!