That's not entirely correct, it's just that racemic ALA's glucose control benefits are dose-dependent. Perhaps only the R-isomer works in this manner, but as regular ALA is half R-lipoic acid, you just need more to do the same thing, and perhaps even more than that wothout chelation (for improved bioavailability).
OP, I use Vitamin Shoppe brand, regular ALA. It works perfectly fine and is cheap; however, they do not make an R-ALA product. I don't know if acne-specific use requires R-ALA, but I imagine you'd be fine with regular ALA, just dosed higher as described above.