The Club have got it wrong on both counts.
Firstly, adding an IR to a JAA PPL is no problem. The exams you take are very similar to the CPL/ATPL exams, but that was always the case. You can either enroll on a course for these, or you can distance learn. Atlantic Flight Training at Coventry have such a course. The IR Flight Test is substantially the same whether you are adding the IR to a PPL or CPL.
The IWR (Instrument Weather Rating), in fact pre-dates JAR, and was an attempt to come up with something similar to an IMC rating, but with rather wider acceptance. It proved to be too much of a bridge to cross, and is now very dead. There are no attempts being made to bring it back either.
2D