Carbonfibre, here is a suggestion
1. Get the standard operating procedures(SOP) from a flight school who does the 15hour IR conversion
2. Find a good UK based FAA instructor(nothing matters as much as this)
3. Use the SOPs from the conversion flightschool(see point 1) and do the FAA IR in the UK. You can do the 10hours of the 40 in a FAA approved PC based training device. Another 10 can be done in an FAA approved flight training device and 20 in a single engine aircraft(this is as cheap as going to the US and you will have been shooting UK approaches and speaking to UK ATC). Written test is easy and flight test is practical. Now you have IMC privalidges in a G reg plane(when you apply to CAA) and a full ICAO IR(this one lasts for life with no expensive renewals necessary - just currency requirements)
4. Go to USA when you can with a safety pilot. Shoot approaches as much as you can, swapping roles with safety pilot. Both of you can log this time legally(ie half price), this is if pilot shooting approaches in under the hood and the safety pilot is rated for the aircraft. Rembering the SOPs(from point 1) all the time. Do as many NDBs as you can find and try somewhere busy like LA(they get predictable IMC conditions also) - forget Florida.
5. Find good FAA instructor and do FAA multi CPL in a/c you will do JAR conversion in(you will get multi IR automatically by doing two approaches on flight test). Remember to use UK conversion school CPL SOPs also.
6. Only do the ATPLs now (unless you have them already) as you have some experience to assist in processing the theory - keep current.
7. Do MCC before CPL/IR in UK - you can't fail it, so use it to reaquaint with UK IFR teminology and procedures etc.
8. Do conversion course at FTO in point 1(by the way, Tayflite is good and they have experience of people converting in the minimums)
Bloody sensible and inexpensive way to get fATPL
Best of luck
Leonardo