whilst you can fly N reg you won't find any for hire easily in the UK. Your goal is PPL only, for fun, right? Part of the fun is the adventure of learning to fly in different places. Don't get hung up on conversion,. also nothing to stop you doing a bit of both overseas and UK training. The USA has better weather but you'll either have to jump the difficult visa hoops/risk money on paying upfront for an I-20 / full time course or accept that you'll have to fly only whilst demonstrably on vacation. Go to Canada instead, much easier. No visa stress, plenty of flying, mixed weather , uk type weather so you learn good weather sense for when you return.. And you can pay as you go at your own pace. The Canadian PPL is thorough and well regarded.