TPK
A PPL(IR) is just a PPL with an IR. You need a Class 2 medical only. You need a Class 1 for a CPL or an ATPL.
Very few people are now doing a PPL/IR; most go the FAA PPL/IR route. There are a number of reasons for this but basically JAA have all but killed the IR for noncommercial pilots.
However, I cannot find in the PDF you gave the requirement for the extra audiogram (which is taken from the Class 1 medical) required for anyone doing a JAA IR. THIS IS VERY INTERESTING and unless this document is incomplete and there is another one, this is clearly a change that's happened in the last year or two.
I have it in writing from the CAA that I can never do an IR, because of having one out of spec ear. I raised this with a CAA official a couple of years ago and the reason he gave me was to make sure people can communicate on the radio - which given a mono headset is demonstrably nonsense.
Your PDF just says
"Applicants must be in possession of a JAA Class 1 medical certificate at the time of the test. PPL (IR) applicants require JAA Class 2. "
Can anyone familiar with this regulation comment?