I currently only hold a PPL, with 58 hours
Hi djwam,
Considering your limited flying experience, the timing of your 'Gardening Leave' is not that good for your stated suggestions.
CPL = You would need a minimum of 150 total hours to start the course.
IR = You need 50 hours PIC
MEP = You need 70 hours PIC
Instead of taking the IR exams, my suggestion would be to do the ATPL Theory Exams (I know people who have completed these, via Distance Learning, within 6 months, whilst working full time). Provided you obtain an IR within 3 years of passing the exams, they will also remain valid for CPL issue (for 7 years from the last time you held a valid IR).
Whilst doing the Theory Exams obtain an IR(R)/IMC and then Night Rating.
Once you have the exams and, assuming you then have the required PIC time, obtain an IR via the CB-IR route - which will give you credit for the IR(R)/IMC course.
Assuming you achieve the above during, or shortly after, your 'time off' you are then, effectively, future proof and can gain any other flying experience and/or qualifications at your leisure.
Although you may have the time for the above, only you can decide if it is worth the commitment (especially financial).