Yes, I noticed that Global Knowledge provides training but it is very limited. I was looking for additional training as well. In particular any links or documentION\BOOKS would be very helpful.
I would recommend looking at FastLane for Nexus trainings. They are Cisco premier training solution provider.
Compared to Global Knowledge, who so far do the training on the Nexus Emulation Software, FastLane offers access
to real physical devices at a lab at Cisco and will soon have their own N7Ks in place.
I did the 5-day DCNI-2 (v3.0) training at FastLane in Frankfurt/Germany 2 weeks ago. We had unrestricted lab access
in San Jose for the whole week.
I would recommend Firefly for Nexus training. http://www.fireflycom.net/classes/cisco.php?js=1. I've been through a couple of their data center classes, and they're very good.
I did the 5 day Firefly training in NJ. WAS GREAT !!! I did the 5 day that consisted of both the 5K and 7K taining modules I think 3 days was dedicated to the 5K and the remaining 2 days for the 7K if my memory is correct. Either way great instructors well knowledged and experience. good guys.
I suppose that greatly depends on where you are located.
In the US, I'd recommend looking at Firefly or Skyline for the advanced training. Firefly is the group who wrote the courses and have extensive deployment work, so that certainly says a lot.