It appears that your use is not a server. Why are you considering loading a server operating system? Would Windows 7 Ult or Window 10 Pro be more useful?
You're right, forgot to edit it, I would go for Win7 Ult.
You need a PSU with two 8-pin +12V EPS connectors, one for each CPU. That Seasonic only has one. You're not running an old fashioned server with multiple high powered spinner SCSI drives, so your total power draw will not be near 600W. I'm only using SSDs in my dual E5-2670, and if I needed more storage all I would get would be one 4TB spinner, so no high power draw there. I'm using a Supermicro 665W PSU I picked up for $35 a few years back at Microcenter.
The Intel motherboard I'm using needs 0.5A on the -12V line to boot up, don't know if yours does, but the 750W Modular EVGA PSU meets that requirement and also has the two 8-pin +12V EPS connectors. Newegg has the EVGA 750 BQ 110-BQ-0750-V1 80+ BRONZE 750W Semi Modular for $70 and it will do the job just fine.
As far as RAM goes, I went for Samsung DDR3-1333 which was very cheap on eBay. I paid $44 shipped for 8 x 4GB (32GB Total).
For cooling, I'm using a pair of inexpensive Cooler Master Hyper 212s.
I see, so as long as I only use the dual CPU and 1 SSD I should be fine with 600w.
Found the same RAM for $50, shipping included. (add 17% VAT to it)
This is very appealing indeed. Unfortunately, Newegg doesn't ship to my country.
I definitely would go for something like that if I could.
I gotta say, if I were buying dual E5-2670v1 today I would be hard pressed to beat the prices of a S2600CP2J with processor and maybe memory from natex. 175 for the motherboard, 75 each for the cpu's. This beats eBay across the board. Memory prices look competitive as well. So, if you have your heart set on a dual lga2011 that is limited by ddr3 memory, then give it a look.
Though, as I said before, I would be more likely to consider something else for a workstation. LGA2011v3 if I had the money. Single socket with workstation cpu if I did not. But each person has different requirements so you have to make your own choices.
Everything is so much more expensive for me though, as the shipping from US to Israel isn't that cheap (and there's taxes as well).
I would look for a LGA2011v3 dual xeon if I had this option, but I can't seem to find a non ES version from the Chinese sellers.
Anyway, after discussing this with a friend, including shipping and taxes I'd have to pay, it seems like it's not worth it.
Especially due to the fact that there is no market for dual xeon here if I decide to resell it.
At least I can resell the i7 6700 to people as a gaming computer if I decide to stop doing what im doing.
The dual xeon would cost me around $1600 and 2x i7 6700 around $900 each.
I'm gonna go with a i7 6700/7700 (maybe i7 5820k) for my next build even though dual xeon would be much better for my needs.
Maybe next time my brother in law goes to visit his brother in the US I'll ask him to buy the hardware for me.
Thank you everyone for your help, I appreciate it!