Alright first off, I would not even get the GTX 580 for this build. You are using a U3011. which is a very high res. So 1.5Gb of VRam will not do it for you at all.
I will get the new 7970 with 3Gb of Vram which is plenty for that res. Trust me, 1.5Gb will bottleneck you in certain games at that resolution (eg: BF3). Plus 1GPU > 2GPUs all the way.
Power Supply. Corsair AX850 - enough for GTX 580 SLI / 7970 CFX.
For cooling, personally I am on the verge of upgrading from a H80 to a RX240. The H series are good coolers without a doubt, but I think that value-wise they are quite poor, considering they are not as good as a Rasa Kit, and just a bit better than a air cooler like the D14.
I would get the RX240, if you can. If you do it right, leaks are quite hard to get. Actually, it is harder to get leaks den not have them from people's opinions.
A D14 is a nice silent cooler that stood the test of time or if you want you can get a H80, if you are going to get a H100, I would rather you spend a bit more and get a Rasa kit.