Just as an FYI. There are so many connectors because it's all 12V. It has to step down the voltage for HDDs and such on the board (afaik) and has output connectors going to the drives. There is a second version of the R940 with a POWER suffix - I suppose the upped the psu for the highest end cpus and to support as many gpus as possible - I think it has up to a 1300W PSU.
Speaking of which, if you want to take a look at those to get an idea regarding the connectors you are looking for model numbers such as CPB09-044A or CPB09-043A or S13-1K0P1A (1000W; power ratings
here) and
DPS-1300JB XX (where XX is A-Z; 1300W; ratings
here). It's all 12V with 11VAUX probably for VSB. But all of those PSUS go for 200-400€. You could potentially rewire an ATX PSU or another 12V only one like the DPS-1200FB (20€ on ebay) and modify the 5V or
12V VSB respectively to drive this board.
For other Fujitsu boards people over
computerbase have been able to do some modifications successfully. Also there might be some useful info
here. Finally, afaik these boards have an 8pin header to talk to the PSU(fan; PMBUS maybe?); I read somewhere that older versions R920 (?) started without it connected but that might not be the case here.
So, anyone who wants to run this board without spending heaps of cash on the proprietary PSU is in for locating a lot of pinouts and trail and error, but it should be possible. I got into this for the R920 a few years ago, but abandoned it after doing the research because it seemed not worth it with chinese x79s popping for cheaper. Hope that's helpful.
Also here's a photo of the DPS-1300JB for reference. As you see it also goes by S26113-E588-V50-01.