Bose & JDJ have it. Up to April 2014, you can fly any UK registered aircraft on any ICAO PPL, but this is limited to private operation, and if you have an IR you cannot use it to fly in IMC in controlled airspace, or in any Class A airspace ["flying in controlled airspace in circumstances requiring compliance with the Instrument Flight Rules" is the precise wording of what you are not allowed to do, so it allows LESS than the UK IMC rating]
Any rental check you will do here is likely to include ample familiarisation, if indeed they know the regulation. Point them to CAP 804, Part I, Section 4, Part Q, Subpart 1, No. 3 [sorry - CAP 804 is THAT convoluted]. They still might not allow you to fly on your FAA licence, though. Just because.
If you want to get a brand-new EASA licence, you need
- an EASA medical
- 100 hours total time
- pass the human performance and air law exams
- pass the skill test [including level 6 English proficiency sign-off]
- you also need to pass the radiotelephony theory and practical exams to get a radiotelepohony licence
Training for the above is "as required", and can be included in the 100 hours TT if you are a bit short. I have no idea how well you fly, but other than radio and one or two procedures the difference between FAA and EASA
PRACTICALskill test are small, in my opinion the European one is slightly easier and there is NO SIGNIFICANT ORAL. If you are current, training should be in the single digit hours, basically familiarisation, refresher and a mock test.
If needed point your flying school to CAP 804, Part I, Section 4, Part Q, Subpart 2, No. 3.
Interestingly, the above is EXACTLY THE SAME as it was under JAR.