Must it be Pukani? That stuff takes forever to cure... meaning, it'll leach phosphates for months, which can lead to a bad algae outbreak if the curing process occurs in the tank. It's best to cure PukanI in a separate container, with a heater and flow but without lighting. Water changes and phosphate tests would need to be done, and hopefully, a few months later, the rock would be phosphate free.
If I may make a suggestion, why not go with Reef Saver rock from Bulk Reef Supply? It's cheap, nice looking, very porous, wonderful to use for rockscaping, and does not take forever to cure. BRS recommends curing all rocks, but most with experience with it say that Reef Saver doesn't need curing at all.
I'm not sure, but believe the reason you're having a hard time finding your desired rock is the ban on some imports from Indonesia.