On the one hand, I think you're overthinking this. On the other, I don't know you, your gun, or its desired use. I have four P-Mags, no idea what part number. (And by the way, they make several different same effect mags, the part number could be color, window, no window, etc.)
To me, a P-mag is a p-mag... I wouldn't worry about it. Especialy since the flavor of the month in AR mags changes more than every month.