Shawn,
Type ratings of any kind for helicopters is a sure fire way to complicate something that needs not be complicated.
The concept that led to type ratings for airplanes has some basis in logic whereas the same would not hold for helicopters. A four engine airplane sure operates differently on one engine vice four....or two on one side only.
Helicopters do not have that level of magnitude of change.
Setting hour and sylabus minimums for training and conversion to new "types" of helicopters makes far more sense than calling the very same training and testing a "type rating".....and getting the guvmint involved.
The UK practice of "type rating" is the best evidence of what is wrong with that notion. It is way too complicated and expensive.
Requiring instrument competence in IFR certificated helicopters....known as an ATP (....or Commerical Instrument Pilot) check ride is a good idea in my view as it is part and parcel of the capability of the aircraft that pilots can be expected to utilize.