Almost all of the fuel cost is absorbed by the school training you, so you wouldn't have to worry too much about that.
UKFT doesn't own any airplanes, and uses a US school, Rainbow Air to supply them with airplanes - and most often instructors too. So if you get a quote for airplane's per hour cost, compare it to Rainbow prices.
I used to work at Rainbow and know those airplanes all too well. Have you thought of NAC Fl.