You should consider one of the Co-Motion Periscope models to give your family some flexibility with which riders can fit on the bike. We recently added a
Periscope Trident Convertible to our fleet of tandems so that we could ride with our 4-year-old daughter. We purchased the bike in the US and then flew back home to Poland with it.
Audrey is so short that we added a child stoker kit, but most kids her age or older would probably fit on there just by lowering the telescoping seatposts. Adults We can also remove a section so I can ride with just one stoker.
The bike feels amazingly solid and handles impressively well, considering the long wheelbase. A triple takes more thinking to get it through tight corners, but most of the time it isn't that different from riding any other tandem.
Riding on the terrible roads we have here in Poland we are very glad to have the sturdy 26 inch wheels and some fatter tires. Plenty fast for the smooth sections of road and offering a bit more comfort on the cobbles, broken pavement and tram tracks that are a good percentage of our riding.
We couldn't be happier with this bike and we are especially happy knowing that we will never outgrow it.