I am pretty sure it is Aaron who is #6...but this is Lost so who knows. In regards to the Jin episode; it wasn't until this last episode that we were even sure that Aaron was indeed Aaron...many speculated that he was Kate's natural born child...so at the time of the Jin/Sun episode Aarons' spot was still sorta up for grabs.
I've already seen the Orchid Video and remember the producers saying that it, along with the modisodes, is the only thing outside of the show itself that can be taken as canon. They also said the Orchid vid will be a key part of the show towards the end of this season
