There's a lot to be said for going to Florida, particularly at this time of year. The consistent weather and consistent hours of daylight, as well as much cheaper flying. It is reasonably possible to do your whole PPL in 3-4 weeks: at-least so long as you've had the sense to do the written exams in the UK before you go out.
This is true whether you go the FAA or JAA route; I suggest that you'd be best looking at the JAA route, since it's easy to get a reciprocal FAA licence from that (see the sticky at the top of the page), but FAA-->JAA, is hard work if you have less than 100hrs TT.
However, what you need to recognise is that flying in the USA IS NOT the same as flying in the UK (and the UK in turn is different to the rest of Europe). In particular, ATC procedures, NOTAMS, RT, airfield joins.... a whole bunch of stuff needs re-learning back home. Plus you'll lose the skills you had at your skill test pretty quickly if you don't use them within a couple of months.
So if you do the Florida / JAA route, and this is not a bad thing to do, you need to add into your budget perhaps half a dozen hours with a UK based instructor at the club you're planning to fly with after you've qualified - basically doing a combination of keeping your skills going and learning to fly in British skies.
On a couple of other points - the JAA PPL qualification is a useful one, the night qualification is nice, and you can do it at the same time as your PPL, but is very hard to actually use in the UK because there's so little culture of routine night flying. The IMC needs a few hours post qualification and the Eurocrats are taking our ability to do new IMCRs in April, so the odds of your doing an IMCR are probably near-zero. There will be some kind of replacement, probably the "EIR" or "En-Route Instrument Rating", but the arrangements for that remain somewhat less than clear.
G