Also LAS started off with a 777-200 with no F and then ended up with a 747 with F and a much bigger plane so I just wonder if there is an F market in EZE (GRU has an F market). There will be a big Y market though down to EZE so I suspect that going from a 3 to a 4 class 777-200 is not sensible and a bigger plane is needed. Also - can a 747-400 get that far??? 6,800 is close the limit of their range isn't it? 777-300 would have no problem from what I know....
FD