The differences between the 330/340 and 320 are limited to which FMGS the a/c are fitted with.
Original 320 fit which is called 'Legacy' is has differences to the recent 320/340/330 fit is called 'Pegasus'.
Having said this the differences aren't that great really and you would easily find your way around one having learnt t'other.
AFAIK FAROS (Pharos?) have stopped supporting their FMGS product. Certainly ours is way out of date!