Search ebay for item # 163498716629 - There is a Tri Mode Duo X in Florida; not sure where you are but that's southern east coast and I think you can mount the joey seat on that model too. If you can find a way to get it from Seattle, I have a complete setup for you for $300.

We ended up with Diono Radian RXT seats after the infant stage because almost nothing will fit 3 across even in minivans (Odyssey for us), but they are made for it and extend all the way to the booster seat stage.

Foundations Quad was what I initially set out to get, and they are OK, but the wheels on them makes it really only good for flat concrete. Just wasn't going to fly. If I was going to buy one big expensive stroller, wanted it to do well on asphalt and hopefully even gravel/dirt trails, which the Valco does.

But a wagon! Yes! The best. Radio Flyer makes one crap, it's been discontinued! WTF radio flyer! Search for it online. It was called the Triple Play, model number 3333 and was here https://www.amazon.com/Radio-Flyer-Triple-Play-Wagon/dp/B00EZIXA78 on amazon. I bet you can find one somewhere. We still use ours all the time for walking to friends house, going to the zoo, the park, the fair, whatever. Been super handy for the last couple years and still is right now. It is big and bulky and doesn't fold up, barely fits in the van, and it's awesome. (Don't worry about finding a canopy, they don't work anyway and are useless) If they ride in it, great. If they decide to walk, still carries all their junk until they need a ride. Best thing ever if you can find one. Watch ebay and look up local JBF sales, I see them there sometimes. If you've never heard of a JBF sale, might be the best thing you don't know about for multiples and saving money on everything you need. jbfsale.com