I've never taken Arginine alpha-ketogluterate, but plenty have taken l-arginine with great benefits in vasodiolation, and load increase --- since it was mentioned.
I would just recommend arginine because it's cheap and people have given good reviews on it. Most of the fancy versions of supplements (ethly-mesterized glow in the dark creatine) are just supplement company hype to make boatloads of cash, and some are even less effective than the original product. There's some exceptions, but as I guideline, most stuff is included (including designer steroids like epistane and methlydrol, but the legality issue of "prohormones" is another post).