Hey Loneline,
I went to the States with a CAA (UK) CPL/IR and because I already had the hours to Qualify for the FAA ATP, I just did the instrument flying training and took the ATP checkride( which is almost identical to the instrument checkride) took the written and got my ATP without doing the commercial first, saved a whole bunch of time and money. I'm 99% sure that if you already have the hours to qualify (can't remember how many it is and my FAR/AIM has gone missing)!!! than you should be able to do this.
Just get your FAA private licence issued and start training on that.
I went to helicopter adventures in Titusville Florida and found them to be very professional.
All the best ,
Fatigue.
