https://www.bikeshophub.com/trailers...ers-c-156.html
https://www.bikeshophub.com/trailers...ers-c-155.html
https://www.bikeshophub.com/trailers...ers-c-688.html
Trail-a-Bikes « Products « Trail-a-Bike

Also,
I have three close friends with families that ride Surly Big Dummies. Lots of child accessories and mods available. Very customizable. My buddies have used theirs so much and made many mods including racks, fenders, disk brakes, NuVinci hubs, etc…2 of 3 ordered the medium so that they can switch off with their partners. One ordered the small as the mother's main ride and he rides a Surly Long Haul trucker with a Chariot trailer, IGo WeeHoo, and Adams Trail A Bike. Exact same setup as I described ours but with the addition of the Surly Big Dummy. They also have a CoMotion touring tandem. We went with the Bike Friday Triple Family Tandem as our other option. Both bike stables work out very well with children.

http://surlybikes.com/bikes/big_dummy

Another one of our friends has a Yuba family bike. Affordable, stylish, etc. I personally prefer the Big Dummy, however it is more utilitarian/mtn bikish.
http://yubabikes.com
http://yubabikes.com/mundo