Also had a quick look at your specs and they all seem good to me. As Chuckfickens suggests your possibly minimal on PSU.
I would go for a minimum of 850 watts, depends on how many GPU's you end up with. Modular cabling is worth it in my opinion easy to do and tidy cable runs. My psu is a Corsair 750watt and its been faultless despite a hard life in my gaming machine. Other makers to consider are Antec, Coolermaster and Zalman. All the cables have fitted connections and its very difficult to get wrong.
The only other issue is cooling, I suspect you will not use the stock cooler for the cpu, so unless your watercooling make sure you have good clearance inside the case to fit the cooler. The 8800 series cards are well known for getting very hot so make sure your case fans are up to it, I've got 4 fans in push/pull setup.
Take your time over the build, especially mounting the Motherboard and use good quality thermal paste on the cpu.
Good luck.
You just made my mouth water at the specs, should make a good gaming machine.