ZZZA/B/C are the only non ER aircraft in the BA 777-200 fleet. I think that it has 17F seats - there is certainly a lot of first class traffic on the route. (17F/48J/24W/127Y against a typical 17/48/40/124 configuration for a 4 class 772.)
http://www.thebasource.com/g-zzzc.html