Hi A69,
You asked "What should I apply for?" and I just wanted to confirm you (and anyone else reading this Thread) were aware of all options before making a decision.
You say you do want to maintain your IR.
This is not possible on an LAPL, as it is a VFR only Licence.
You say you do not want a Class 1 Medical (I understand why).
So an ATPL or CPL is not possible.
Given the above your only option is to have a valid Class 2 Medical and to apply for a PPL.
There is no need to wait but, before you apply, make sure any Ratings you will wish to use (eg SEP, IR) are, or will be, valid at the time of Licence issue.
There is no problem Renewing them later if they are not valid, it is just that they will now be recorded on the back (rather than the front) of the Licence and it will therefore require additional CAA action (and cost) to reactivate them.
Also consider whether you want, and already qualify, for any new EASA Ratings (eg Aerobatic). If so apply for these to be added to the Licence at the same time. No additional cost if done this way.
Good Luck