I use a double Baby Jogger - it's quite heavy but very sturdy with a lot of basket space and is a smooth ride. Won't be good if you live in an area without ramps or a lot of high curbs, though. I also had a chance to try a Phil and Teds double stroller and it was much lighter and an overall easier ride, but it had very little basket space and a three-wheeler needs a bit of time to get used to.
I'd get sturdy high chairs that would look nice in your house - Stokke, Mokka or similar. They grow with the child and look like regular furniture, so it won't look like you have a daycare in your house. Or something stackable like they have in restaurants, which would probably be much cheaper, albeit less nice looking.