If at all financially possible if I was you I'd look into renewing the MEP/ME-IR. This would of course give you more options than just having the SEP/SE-IR and you wouldn't have to worry about the CAA turning around and saying you need to do x,y,z to get your MEP/ME-IR back because you let it lapse for greater than 3 years.
The other problem you face is that single engine jobs are usually single crew and whilst I can't be 100% sure I believe that in order to operate commercially single crew I think you need 700 hours total time (maybe also 100 hours IFR?). I might not be totally correct with regards to this requirement but I'm sure someone on here will be able to correct me.