Short answer: GCI is out - runway too short; JER's runway is a little shorter than desired, but FR did look into JER a few years back, but JER authorities would not bend over as far FR wanted them to and in the end, no deal. I think JER recognised that FR would probably chase away all of the other carriers.
By the way, a little heads up: Channel 4's Dispatches will be broadcasting a programme next Monday on FR's fuel policies ... ad included some excerpts of interviews purporting to be with pilots ... cue injunction threats by FR's lawyers (all no doubt adding to publicity) - should be interesting to watch, even before the programme ...