TF, just come back from FL, BA, non stop service to Orlando from LGW return, 250 quid. I have previously paid similar for the time of year you will be flying, as always it is a question of shopping around. Even though BA and VA tend to be direct, going via somewhere like Chicago, New York is no big deal, have done it that way as well.
I must add, I was pleasantly surprised with the service from BA after usually being a VA man.
Just out of interest where are you going to finish your PPL, and have you checked this place out? Just a thought.
I have done a lot of flying in the US and you will definately have fun.
Happy Flying