The two rifles ARE NOT THE SAME.
The SLR-101 are Bulgarian receivered rifles that are brought in as single stack thumbhole stocked guns that are then milled out to accept the standard capacity magazines and have enough US parts installed to be legal with the pistol grip.
The SA-M7 and M7S are rifles that have newly forged and milled receivers made here in the USA by Bulgarian technicians. They are then built using Bulgarian barrels and parts, all of them new, with enough US made parts (again made by Bulgarian techs to Bulgarian specs) to have the seperate pistol grip stock set.
The SA-M7 series are also better fit and finished, and the cleaning rod fits up under the barrel as well.
If you can swing it, definitely go with the SA-M7 series, but the SLR-101 is a nice rifle too, but you get what you pay for.