process
here's the process for you, since there's a lot of people doing this at the moment.
1. Do the 14 exams, either first or at the same time as flight training (if you can handle the load)
2. Go to Florida and get your FAA commercial multi with instrument.
You should at this point about 270 hours.
3. Then get the CPL ME conversion there as well. Naples Air Centre, FlyOft and FlyEft do them. (i recommend contacting Mark at Naples. He will give you the best guidance)
4. Fly to the UK (emphasis on UK. DO NOT CONSIDER MALAGA!)
Get your IR there. PFT in Bournemouth has the lowest price i've researched. 4500 GBP including 170A/skills test and landing and appch fees.
5. Jump over to the CAA in Gatwick and enjoy the tons of paperwork.