Wellone definate bit of info is that you are not allowed a J1 visa if you already have over 100 hrs and anything more than a PPL.
The good bit: With your super dupa JAR lic for 6000$ approx you can get your CPL,IR, and CFI, and for another 3k your CFII. So for approx 5 grand UK you will be in the position to teach in the US if you hold a work permit.
There was a rumour last time i was over there that when JAR finally decides what to do with the US training one of the ideas may be that the only instructors who are allowed to do jar training will be jar trained FI's. Who of course will need to be CFI's to comply with the FAR's.
This should stop the students having better technical knowledge than the instructors
MJ