the 2000-B is a trainer version based on the -C, it has the same systems and hasn't more AG capability, even less as it losses its guns.
The N is the nuclear detterance one, the latest ones can carry unguided bombs.
it is propably the -D you are talking about, it is a dedicated AG version ( AG radar ) based on the -N, but is a lot more recent than the C, still in use, and will probably stay in use for quite a long time. it is very unlikely that RAZBAM could make it, IF they wanted because the avionic/radar would have to be done from scratch.
if there was a second version of the same plane to be made, it would be better to make a mirage IIIE, the upgraded multirole version of the mirage III, with better avionic ( RWR ), better A-A radar, better AG load out including guided and anti-radar missiles. It would also be a better opponent to Mig-21bis/F-5E-3/F-4E than the IIICJ.