You will probably want to change out your cooling to something like this ERM-3K3UC Liquid Cooling System, Copper that you can find here -
http://koolance.com/erm-3k3uc-liquid-cooling-system-copper - and get you some copper water blocks for the cpu's and the video cards. Those cpu's and video cards are going to produce some serious heat and the best way to keep that system from overheating will be liquid cooling. (Unless you don't mind the jet airplane coming in at several hundred dB's sitting next to you). Then you can use the regular cooling fans in the case for the NB, SB chip sets and memory.
Not sure why you are getting the WD Sentinel DX4000. It is a server/computer all by itself. What you are doing is actually buying one computer and building another. You can just as easily buy 4 - 4 terabyte drives (16TB), and add them to the 4 SSD's to put them in the computer you're building instead of getting a second server.
Your psu is going to be at it's limit with power connectors. The video cards are going to need 4 - 8 pin plugs, the motherboard will require 2 more 8 pin plugs plus a 6 pin plug that will be required for the motherboard operations. Unless you're planning on getting a handful of 4 pin molex to pci connectors to make up any extra needs? Then your concerns will be the power draw on the 2 rails, just make sure you balance them correctly as each video card will require 30 amps all by itself. You might be better off getting 2 - 1,000 watt power supplies. I would rather go with 2 of these Thermaltake TR2 RX TRX-1000M 1000W ATX 12V v2.3 / EPS 12V v2.91 SLI Ready CrossFire Ready 80 PLUS Certified Modular Active PFC Power Supply that you can find HERE -
http://www.newegg.com/Product/Product.aspx?Item=N82E16817153118&nm_mc=KNC-GoogleAdwords&cm_mmc=KNC-GoogleAdwords-_-pla-_-NA-_-NA - They each have 2 rails @ 50amps and each psu has 3 x PCI-E 8Pin, 3 x PCI-E 6Pin and 3 x PCI-E 8Pin to 6Pin + an 8 pin motherboard ATX plug so all your requirements will be met and have spares for future upgrades later. Your case is already set up for 2 psu's so that's covered as well.
Why are you cheeping out on the optical drive? You are only getting a DB reader and not a writer? Might as well get an all purpose and buy the Double layer BD writer. And you probably want to get two of them in case you need to burn from disc to disc.