Oneday78,
It's quite possible to do the PPL abroad in 3-4 weeks. I did it in 4 in the US but certainly could have squeezed it into 3 weeks.
If you want to do a JAR licence, which is a minimum of 45 hrs training and 7 exams, then there are about 10 schools worldwide that are approved by the UK CAA to carry out the training. If they're not approved then you would have to train for an FAA licence, if for example you went to the US. The list of schools approved for training is
here. .
There's no problem with getting an FAA PPL, and it can be used in the UK. However, you may wish to convert it to a JAR PPL on return to the UK. To do this you have to do the skills test, and if you have less than 100hrs, all the JAR written exams and RT test. If decide to get a JAR PPL after gaining 100hrs then I believe you only have to do the skills test and the human factors test, and possibly the RT too. But check on that.
If you decide to do a JAR four-week course abroad, then you can either take the exams whilst your out there, or do them before you leave. If you choose to do them out there, which is what I did, then I would strongly advise studying before you actually leave to start the flying training. Get hold of a set of Thom or Pratt books.
As WWW pointed out, with the exchange rate so favourable, then it would be financially a good choice to go to the US.
Good luck,
No. 2