As far as I am aware I don't think you need
to be an FI in the JAA countries to be a sim
instructor
What you do need is
To have held an IR
Airline experiece is a big plus
You will have loads of street cred
Contact Oxford or BAe or Cabair for advice
There maybe a demand on airline sims as well
contact the CAA
These jobs can pay quite well !!
Good luck
Let us know how you get on