Don't go to any of the JAA schools for hour-building, they are quite a lot more expensive than the FAA schools. If I were you I'd first build my hours in one of the cheaper FAA only schools in Daytona Beach, for example. Try
flyaussieair.com (website down at the moment apparently)
or
Air America Flight Center, LLC - The Leading Flight School and Aircraft Rental Center in Daytona Beach, Florida They're decent and cheap, I know people (students and instructors) who have been there. You can take the planes overnight and do some really long cross-countries (Bahamas!), something that is impossible at OBA as you only get $3 back per gallon (pricey).
Just make sure you have applied for an FAA PPL licence before you get here, otherwise you'll be wasting your time (very common mistake for JAA hour-builders) as you need that piece of paper!!
As for CPL and ME, I only know about guys who have done it at OBA. Good instructors, though plane availability is a problem at times, and of course don't be foolish to think that Florida weather is perfect. It's not, sometimes you lose a whole week because of weather (granted, mainly during the PPL stage when doing solo X-countries, this is less an issue for CPL. That said, when I was there in April some CPL guys had been there months and were not happy at all).
To be honest, I would only build my hours in Florida, which is perfect for that kind of thing (just challenge yourself to go into busy airspace, go to Jacksonville or Savannah, good fun. Don't simply burn holes in the sky but plan proper routes, maintain a set altitude and heading, etc.). CPL I would do in England as you'll need that experience of the British airspace.