I never suggested you should fly a R22 (even if you would fit in one), and I can fully understand as to why you train on a 500. I'm wondering would they let you rent a 500 in the US with a PPL and only 40-50 hours?
Chopperpilot47; the only reason to convert was for purposes of getting the foot in the door with a UK school. You don't have to convert but in the UK a lot of schools have a grudge against the FAA license. (Totally ridicilous)