If you want to achieve the ultimate goal quickly and money is no object, forget the IMC/IR(R) - it's a waste of time.
There is no such thing as a quick IR. Too many IR schools, to make it harder to achieve, operate Monday to Friday and keep weekends sacrosanct which is unhelpful. The very little spare time very busy people have is usually at weekends. There may not be a IR school near where you live, because of an elite attitude by the NAAs, nor an exam centre closeby. The commitment to achieving an IR is disproportional to the need for too many people.
If you do not need to transit class A airspace and particularly if your flying is confined to the UK airspace (including the Channel Islands, I.O.M and Northern Irelancd) then the IR has littler advantage. The IMC can be taught and tested at the local flying club 7 days a week as can the written examination. The skill test is also likely to be accessible locally. The safety record of the IMC rating speaks for itself. If it suits your purpose then it is all you need.
Decades ago the U.S. realised that maintaining a IR as an elite rating was a bar to safety. People continued to die in IMC related accidents. The U.S. IR nowadays is an accessible rating to all from when the onset of the PPL is gained. The candidate can train for the IR at their local club arranged within their availability. The U.S.IR process is designed to be accessible to all and because of this the US has an exemplary IMC safety record.