Aomori is the type originally used for making black garlic in Japan, though I've had success with many different types across families. Aomori is distinct from Japanese aka Sakura garlic- Aomori exhibits a bit of pinstripe coloration on the outer wrappers, with more elongated cloves compared to the squat Japanese/Sakura ones. Quite mild, plays well with others in light sautees. I look forward to doing up a batch of black garlic with it to see if the rumors are true- that it makes the best black garlic due to sweetness coming through (and perhaps the reduced amount of sulfur?).
For growers, it's useful to note, it makes rather nice bulbils that make for good planting. Sow them thickly in rows, and you'll get tons of pearly rounds and doubles that will net you nice medium bulbs and larger the next year (or you can always eat them, too). They're a bit smaller than some of the Asiatic bulbils out there, but that's fine, makes them even more likely to hit the sweet spot of forming rounds the first year- which means best outcome in the second.