From what I've heard Walt Smith isn't shipping any live rock anymore, international air freight just costs too much these days. He's only shipping it by the boat load and shipping dry artificial rock.
Some live rock coming in from Manado which you can get from premium aquatics and some coming in from Bali through Vast Oceans in the Seattle area.
Other than that, your stuck buying dry rock, recurred dry rock, or artificial rock.
Real Reef is a real ripoff considering they're not paying any air freight at all and still selling their rock at the same price as ocean harvested live rock.
Marco rock is very porous like pukani, but it has been land locked for thousands of years at least and any nutrients that was in it has long since been washed out.