Well, I have an extremely similar rig to yours and mine runs skyrim at ultra. All i would recommend is to get the 965 be that i mentioned.
Get the AMD Phenom II X4 965
I also recommend you downgrade windows ultimate to windows 7 home premium. It'll save quite a bit of cash. This can then be used to upgrade the more important components of your build...CPU and GPU. Windows Ultimate is more or less for enterprises and businesses.
Get this monitor...Asus VE228H 21.5"
Get this GPU...MSI R7870 Twin Frozr
Step that RAM up to something like this...G.SKILL Sniper 8GB