Ah, but those aren't Luxeon emitters. it looks like they took seven lower power emitters, and arranged them on a single (large) heatsink. Luxeon emitters are capable of the same output, with lower current requirements, in a smaller package.

As for the K2s, see how all the prices say $call? That's because they're not available yet. I confirmed this by calling them myself a few days ago. They said they already have quite a few backorders for these things.