Bellend - you will need to have an FAA private pilots licence issued on the basis of your JAR licence. I'm afraid it's a while since I got mine so there's no point telling you the route I had to take as the rules will certainly have changed. Knowing how long administration can take (in any country) you will need to get the ball rolling now to ensure a flight or two.
I use sunstate aviation out of Kissimmee airport when in Orlando but any of the local schools will have websites or be happy to chat about prices.
Regards, enq.