if you're going to fly in this country then it would be better to train here as you'll be used to flying in this weather. no point flying in sunshine all day every day when you're going to be bumbling around the uk skies.
best thing for you to do is visit the local flying schools and find out what the JAA/EASA PPL is all about. the quality of aircraft they have. the costs.
the US may seem cheaper but living costs, expenses and so on won't make it that much cheaper.