Must Find/Buy/Make

I got our bikes out of storage today. Filled tires, re-fitted kids, gathered supplies and we were off on our first bike ride of the season. Oh how I love biking. I think it is my favorite mode of transportation. I would love to see the world on a bike. Has the same charm of hiking but you cover way more ground. Every year particularly at the first of the season, I have moments of decreased productivity as I am caught away day dreaming of biking far distances with my kids, or summers of no car usage and so forth. Then I try to figure out how can I do this today with young kids - a couple of free-loaders with only fair endurance? And so I design in my head ways drag everyone with me. 2 years ago I came up with this and we are still using it today. It was/is great but there are two problems. I can't stand up to pedel making hills even harder then they already were with an extra 100 pounds. And 2 Xander is now almost 4 and is pretty much too big for the chair and he is ready to start pedeling. Soren is still on training wheels (this summers goal) and for any long distances would need the option to hook up even if he was off traning wheels. So, we need a new plan.

Upon researching options that have already been made I found this picture

I want this. Correction - I must have this!! Oh my word - I love it. double wheels in the back to increase stability and you could carry gear. Sign me up! Sadly they have stopped making them years ago and they are very hard to find. Disturbing news I know, and yet I don't feel limited. Hmmmmmm, could I make this or something like it? My brother in law does have a welding machine. The wheels have begun turning. Excuse me, I need to google now.