V2, im assuning one of the reasons why you wanna go to the us is because the ppl can be done a lot quicker than in the uk, due to the weather.
Have you thought about doing it in spain, which has the same advantage?
A number of flight schools offer a 3-4 wk PPL with British instructors, such as
www.fly-in-spain.com, down at Jerez.
The training cost I think comes out at about a grand more than places like OFT and Naples, but once you factor in US flights ((around £300) and visa charges ($337 for the visa plus $180 for registering with the alien flight student programme) it might not be too much of a difference.
Plus in europe u will get more experience of flying in controled airspace, of which there is not a great deal of in Florida. A lot of people say that someone who gets their PPL in the US is advised to take a couple of hours of instruction when they get back to the uk to get used to the difference.
Am out there myself in a week or so to do quick PPL with Fly in spain, will put my thoughts about it on pprune when im done.