Flight Training
I did my PPL and Hours in the USA - Used EFT for the PPL (took 5 weeks) and can recommend them as a good FTO and used Sunrise Aviation (Ormond Beach, Florida), for the hours - (Took 3 weeks to do 75 hours @ £35ish and hour!!!)
Currently doing the MultiCPL/IR in the UK and am having no real problems adapting. Only needed a brush up with the RT and adapting to the airspace but that all came as part and parcel of the CPL training. (CPL has taken 4 weeks but have been fortunate enough to fly every day)
If you want to do the american route then Id definatly recommend that you try and do around 10 hours of your hour building in the UK before the CPL - this will help in the RT proceedures as well as local familiarisation - good for the Nav side of things. (That is if you decide to do the CPL/IR in the UK like me - I just feel that it is practised to a better standard over here).