@Garfs
Go to the US, get your IFR.
Go back to the UK, take ALL of the IR exams, hit the Sim for 10 hours, fly 5 hours in the Bell 206 and youīre done.( 5 hours more if you donīt have a 206 rating)
download
http://www.caa.co.uk/docs/33/LASORS_06_WEB.pdf
and read section "E"
Thatīs called a single engine IR, IRīs are type specific, you can upgrade to a twin IR in the aircraft you will actually fly.
Cheers