I would do some serious homework FIRST before setting out on this adventure, and then get a 2nd and a 3rd opinion! I suspect if you are already a helicopter pilot (PPL) then you might not get the work permit from the INS, you might have to be enrolled in the whole CPL course first (and not PPL to CPL) to qualify for working privileges in the US. Anyway, that is what I was told by a few reputable flight schools. So I'd be aware before setting out, things will never go smoothly and according to plan when you eventually get to the US, you can be assured of that!!