I noticed that Manston is missing from your list of prospective airfields.
Although I've only just started my NPPL , I have been very impressed by the folks at Manston all are very helpful and the facilities are great.
I live in Gravesend and it's a cheaper for me to learn there rather than Rochester or Biggin Hill.
Have a look for yourself @
www.tgaviation.com/frames.htm
PeterJ