The only thing I'd suggest, as the previous poster, is trying in windowed mode. I play 1920x1080 windowed and haven't had any crashes since the first day or two of Open Beta. I'm keeping everything on max settings otherwise, and not having issues with lag or crashing.
My specs are less than yours, aside from the GPU:
AMD Phenom IIx4 955BE (overclocked to 3.9ghz),
4 gigs low latency (7-7-7-21)ram,
MSI 790fx-gd70 Mobo(highly recommended if you ever go the AMD route),
and a EVGA gtx470 gpu, just slightly overclocked;)(anything more would be PC suicide, because this GPU gets hot;)
Even still, I'm running 60 fps in most areas, 40-50 in areas with heavy load. The first day or so of Open Beta I was running a little laggy, but it's improved a ton since then.
Best of luck to you, and PM me if you have some questions about Overclocking or system tweaking(I build these machines for a living, so it's all up my alley).