What are you planning on doing with that system? There's a chance I could save you from wasting a bunch of money. For example--starting out with dual cards is often not the best choice. Also, an i7-2600K doesn't game at better framerates than an i5-2500K.
You're getting the non-SE GTX 460 1GB cards? I guess if you picked those up on the $100 deal a couple days ago, that's a great deal--Although I'd still take a single GTX 560Ti for $183 over dual GTX 460 1GB's for $220 (since only one will get the rebate to make it $100).
Make sure your PSU is a good one. That means Antec, Corsair, Seasonic, or XFX. (There are some other brands that cost more or tend to be good, like Silverstone, Enermax, or PC Power & Cooling, but me saying this will just complicate things unnecessarily). You'll probably want a 650W one--XFX had a good one for $49.99 after rebate last month.
Get solid RAM so long as it doesn't cost much more. At least 1600CL9 or better: http://www.xbitlabs.com/articles/memory/display/sandy-bridge-ddr3_7.html#sect0
4GB is good enough for a gaming machine, but at today's prices, 8GB makes more sense.
As for the OS--don't get Ultimate unless you know what you plan to use the data encryption benefits for.