I would add Enstone and possibly Wellesbourne to your list. Enstone is no further than Kidlington and whilst Wellesbourne is a bit of a treck Wellesbourne aviation is a good school and the cafe is great for those non flying days.
If you are around this evening the Wiltshire flyers meet at the Harrow Inn in Wanborough at around 19:30. I am sure that people there will be able to point you in the right direction. Ask for Duncan.
Beware if the microlighters who will try and turn you to the dark side
