Yes, R200S is just the short nose version of the R200 as was used in 240SX, Skyline, etc.
My end game is to get a way taller gear & retain LSD (my current diff is VLSD with 3.54 gear). With my current transmission & tire size, I don't get much use out of 1st gear. Something way taller like 2.95, 3.13, etc - not married to a number, but something in that range while retaining LSD is what I'm after.
RE: "looking at a spec sheet, a lot of different vehicles had the R200 but different internal ratios." Is there an online reference to that spec sheet? And does it indicate which ones had LSD?