IBM xSeries 350 / Netfinity 6000 help needed

I found this motherboard on ebay, very cheap, or so I thought. Can take 4 Xeon/Pentium III slot 2 processors. Turns out you need multiple ancillary boards for this to work. There is a small section of the freely available (8682) hardware manual that describes a minimal bootable configuration, which eluded me initially. So I bought too many boards, but don’t have what I need, presumably, according to the manual. I’m wonderimg if I can get away w/o the power backplane and power supply, as I’d rather just hotwire an atx supply in their stead. Anyone have specific knowledge of this machine?

I already have a set of 4 nos cpu’s, that are faster then the x350’s rated speed. Insufficient ram sticks at the moment. I do have the memory board, led board, and diagnostic card.