Thanks Trim Stab.
I'll probably do as you recommend SEP CPL/IR and save the MEP rating and IR until say 6mths before my exit date.
Whilst I can find info in the CAP relating to renewing a lapsed IR ie. Training with an ATO up to the equivalent standard to pass the initial test, I can't find anything relating to renewing a lapsed CPL ie. I didn't keep a class rating for a part-FCL licence. Is it the same as the IR? ( I don't plan to do the 12hrs + 1 with an FI in 2 years)
Ultimately what I want to do is: ATPL exams SEP CPL & IR then not do anything with it for about 6years (I'll be current on Mil SE and Twin Jet with Green Unrest IR, but not flying a SEP - not that it appears to count for anything) then pick up where I left off, renew my SEP CPL/IR then go down the MEP rating & IR + MCC + some luck = job. I don't, however, want to do the ATPL exams twice. If its is not possible I'll just wait until nearer the time. I'm just keen to do them now as my brain is in study mode and my current job would allow the study time/leave.
Thanks for the replies so far.
For the record i've no massive infatuation with the DA42, it's just reasonably priced

and has a modern glass cockpit - something I'm familiar with.