Going to the US for your PPL is a great way to get it. A few more words of advice
1 By all means do some flying before you leave the UK. In the USA complete all the training to get your US (FAA) PPL. ie don't just do some hours and come back. If you get your US licence this will allow you to fly over there when you visit. Also you can then just sit a couple of UK exams (air law and RT I think) and then the CAA will issue a UK licence. You can legally fly in the UK on the US licence as long as you keep it valid (medical and certificate of experience. I did this for many years.
2 Choose a school in the US that has a reasonably busy airport so that you learn how to cope with a busy airport. The best analogy I can give is learning to drive in a busy city will ensure that you are confident to drive anywhere. Learn in the quiet country and you'll be scared of driving in towns. Learn to fly at a reasonably busy airport (ie one that has a tower and ATC) and you'll be confident to fly anywhere thats busy.
3 Allow 3 weeks in the US, don't expect to do it in the minimum time (ask the school what their average number of hours for recent PPLs is). If you want to get your PPL in the minimum time then be prepared to be at the airfield from 8am to 8pm and studying in the evening. Don't take your wife and expect to spend much time lying by the pool with her, you will be busy and quite tired in the evenings. Its great fun but probably not for anyone who is with you and not learning to fly.
4 Aim to get your licence in March/April. This will mean you come back to the UK with the good weather ahead of you and can build some experience with sunny days and long evenings. If you get your licence in Oct/Nov then when you get back you will not be able to fly much in the winter and will get very rusty and have to pay for a refresher course. This means you have to find somewhere that has good weather in Feb/March, hence Florida or CA are the favourites.
5 Don't pay in advance.... Don't pay in advance
I suggest paying by credit card as you go. Some schools allow you a better rate if you pay $500 at a time. Work out how much you might save vs the risk of losing it if the school goes out of business... and don't expect a refund if you have anything left in your account when you leave... they expect you to use it all on flying so plan for this.
6 If you can do a day or two of flying around at the end of the course then do it. Getting experience helps you remember what they taught you. Also if you forget anything the school is there to refresh your memory.
I do like Sunrise aviation (
http://www.sunrise-aviation.com ) at Orange Co (John Wayne) airport in south Los Angeles. I go there for aerobatic training and they seem nice honest people. I don't know what they are like for getting e new PPL but they have a lot of foreign students and the airport is busy. You can also get some tailwheel and aerobatic instruction there... Try it They will train you in a piper cub for the same rate as a C152
Have a great time.