Thanks for your suggestions guys. I have edited a few things, so here is my new list.
I skimmed it over, the main thing I can safely recommend is a power supply with higher wattage. The wattage calculator may have recommended 390w, but that doesn't mean you should then get a 400w power supply. Not supplying your parts sufficient power will cause severe damage to all of your parts, I recommend getting a 500w power supply at the least considering what you are aiming for in your build.
And here is one question to throw out there; why can't I run Battlefield 3 when my system exceeds the system requirements, and comes close to the recommended? Do I need to update my graphics drivers? I get anywhere around 10 - 30 FPS when playing.
Many games won't perform optimally even when you meet the recommended requirements. You just have to keep the graphical settings low.
EDIT: Oops, didn't notice I was a page behind.