On the Trans-American Electric Bike Tour in 2012, 2 of our riders traveled 4,000 miles from New York City to San Francisco pulling heavy loads on 2 different trailers. Imagine months of riding, mountain passes, and a lot of stuff. They used products from Burley and BOB. Links to their sites are below. For mounting purposes and the unique style of our bikes, it is important that the trailer attaches to the rear axle, not the frame.
I encourage you to explore their product lines to find a model that fits your needs. I think you will be pleased with the quality of these companies.
To use the B.O.B. on a NuVinci equipped bike, you will need a set of the B.O.B. Nutz, 10 X 1 Metric: http://www.amazon.com/gp/product/B000RH5DP8
This trailer would be very versatile and would work quite well with any of our bikes: