I just came across an ask you answered in the sao tag, and I am intrigued by the mention of this 16.5/16.6. Is there an English translation of it and where can one find it?

You can find a many of the material edition stories on tap’s website.  (material editions 1, 3, and 10-13.  This includes 16.6.

The infamous 16.5 is also on his website.