I assume you would want to operate in Category A. One of the UK requirements is that you train and demonstrate Category A with your pilots.
Unless things have changed drastically, there is no way to do this in the real aircraft. The engines have 30" and 2 min One Engine Inoperative Ratings, and the certification rules require that these ratings only be used in a real emergency. Training does not constitute an emergency. Nearly every other helicopter with these ratings incorporates a training mode switch to make the FADEC simulate the engine failure condition. Not the Bell 430.
If you simulate engine failures by retarding a throttle you are doing two things - a) violating the flight manual limitations, and b) putting the engine into an area that will potentially cost you thousands of dollars per second of operation - the engines have very short life in the 30" rating (total of 2 to 4 minutes) before they have to be removed for overhaul.
And I don't believe the CAA has accepted the only Bell 430 simulator (in Fort Worth) for Category A training - could be wrong on this.
So, you could buy the 430 but not be able to operate it in the UK.
If you want to correspond about this privately, send me an email off line.