Tough decision, but it looks like it may be Seasonic. I need to email that company though to see what it would cost since the splitters would be cheap from monoprice. It doesn't look like they sell Sata to Molex only the other way around.
The BTOS/Seasonic Molex spare cable is here ($5). Both Seasonic & eVGA SATA/Molex source connectors on the PSU are interchangeable as I noted above, so a combined total of 3 or preferably 4 of those connectors on the PSU is enough.
You should ask eVGA if they will provide additional Molex cables (because only one is included). Alternatively, no matter what manufacturer, these one-to-one SATA->Molex Monoprice cables are fantastic. I used them for ~3 years when I didn't have a modular PSU in my 4224. Cut off the floppy connector unless you need it, and wrap some electrical tape around the SATA-SATA connection to ensure it doesn't slip off while you're working inside the chassis.
If you're on a budget and OK with a fixed mobo cable but otherwise modular, this eVGA 650W looks good for $60 after rebate. Add 5-6 of the Monoprice SATA-molex cables for ~$12 shipped and you'd be set.
I didn't find it hard at all to modify my Supermicro case to make it quieter.
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I simply removed the [846] stock fan hardware and put in a Norco 120mm fanwall which fit perfectly fine unaltered.
Well, if you rip out the PSUs/PDB, of course the Norco fanwall will fit (as it will in almost any 4U chassis). I'm not ready for that radical a solution yet