Ok, lugs first.
Your standard M1A receiver has just the as-issued legs in the middle of the receiver.
Next up is adding rear lug(s).  
Final step is adding front lugs to the above.
It would take a damn good shooter to notice any difference between them.  Some claim the more lugs, the longer-lasting the bedding job.  As against that, it's a royal PITA to inlet for rear and front lugs.
Super Match rifles do not necessarily have any lugs other than the standard.
In sum, it's an expensive upgrade only the finest of shooters can make use of.
As to NM/SM, the SM simply has more bells and whistles.  It is simply a NM with additional work done to it.  Again, useful for the excellent shot and competitor.
As one refines the rifle into a dedicated target rifle, one necessarily leaves behind some of the military charicteristics such as robustness and reliability.
If you wish to compete, forget the M1A, as it's outclassed on the target range by highly modified Match ARs.
Most shooters would be better off buying a standard grade M1A, swapping out the non-milspec parts for the USGI equivalents, getting a trigger job, and slapping the barreled action into a good, tight-fitting USGI synthetic stock.
One other thing.  Match rifles most often are chambered for Match ammo, whereas the standard rifles most often have a somewhat looser GI-spec chamber.  You might well find that your Match M1A does not digest ammo that will work reliably in the standard rifle.