BA 747 entertainment

Hi all. Next week im flying from LHR to Miami with BA. I have been told its a 747, do they operate -200’s/300’s or is it guaranteed to be a 744? Also, do you know what the inflight entertainment is like? We are travelling economy (but there is always the chance of an upgrade! The guy im flying with flew with them twice earlier this year and both times has been upgraded to First Class from economy! Not bad!)