So with this design the double scroll is left out. Does that mean I need two PSU's, one for each board? Or is there an adapter that would work?
The double scroll holding the two boards would only require one plug for the whole miner.
Look back a few pages. The miniplane and double scroll have been switched to two PCI-E connectors now instead of ATX 24pins. Change happened with the switch from 5v to 12v. A nice single Power Supply that's ready for SLI GPUs with four or more PCI-E 6+2 will work nicely with the double scroll or two miniplanes (especially the very efficient Seasonic ones).