It'll have to be completely standard, all the factory emission stuff has to be in place and it'll have an idle CO2 and hydrocarbon test as well, which it will pass with the facotry ECU in place.
It should be just an inspection though and no engineering will be required.
I'm getting all the parts togetther to do a RB25 conversion on a 180sx so if you need some of the factory stuff then i have pretty much everything provided your 25 is a series II.
EDIT! (now that i've actually read your post)
You will need to remove the FPR and you will need to put the standard ECU in (infact when you produce the car to be inspected you have to allow the easy access to the ECU I.e. remove the kick pannel). It would be a good idea to find a factory turbo and fit that as well.