6 weeks should be more than enought to get your PPL done. I got through mine in 4 wks (even though I had to split into 2 x 2wk stints due to work refusing to give me a block of 4 wks off!).
My one thing, which I have said before, is make sure that you have all the written exams complete before you go. I was flying approx 4 hours a day and being able to relax at night was great, other locked themselves in their rooms and were cramming hard. Its a big bonus card to hold.
I have noticed the cost steadily rising since I completed my PPL about 5 or so years ago however I still think that the cost are cheaper. The other big plus I have found is that schools over there, at least in my experience, tend to have newer and better equpipied and not to mention more aircraft for students to use. My experience of the UK flying school scene has been offputting to say the least.
I, for one, am a fan of the intensive training regime. Constant exposure to the flying environment day in day out improves your skills rather than letting them fester whilst you wait weeks since your last lesson for a break in the weather. This was certainly a big help when I completed my IR which again took about 2 wks and I think about 60hrs flying.
As IO and EA say, the places to visit whilst underatking your PPL are fantastic and you dont have to spend all day flying in circles round your airfield - make something of your trip!
J.