Do you hold a UK issued JAR CPL?
The UK CAA are still working with amendment 3 of JAR FCL 2. (You can confirm this in LASORS) see page 6 of lasors.
http://www.caa.co.uk/docs/33/LASORS_07.pdf
If you sit the 7 IR exams, do the flying part of the IR course and get the IR issued. You will hold a CPL(H)/IR with an ATPL(H)/IR Theory credit.
The ATPL(H) theory credit as far as I remember lasts 7 years from when you last held an IR. So as long as you keep renewing your IR your ATPL theory credit will not run out.
CPL(H)/IR is good enough to get a job as a first officer on the North Sea, When you gain the required multi crew hours the CAA will then issue an ATPL(H)/IR.
This is what I had to do, I advise getting this in writing from the CAA just in case it changes in the future, however if you start this while the CAA are still working with amendment 3 of JAR FCL 2 you will be able to complete things under the present rules even if/when they start using a latter edition of JAR FCL 2.
I had this confirmed in writing from the CAA.