It is really questionable that you need
to upgrade at this point as virtually only your RAM and GPU (ranked 31 in PassMark G3D benchmarks) are not optimal!
It depends what sort of upgrade are you looking for? New Hex core, I7, MB, CPU, GPU etc?Cheap solution
Double your RAM to 2 X 4GB
Sort out your fan profile on your GTX560ti so that its quieter and wait as long as possible before buying a new GPU - (NB: this will require saving the balance of the budget rather than agreeing to the GF's request to buy a new sofa with it)!
Let the GF choose the case to match the decor of the living room (cheapness not guaranteed of course)!Quiet solution
Double Your RAM to 2 X 4GB
Either sort out fan profile on your GTX 560ti so that its quieter and wait as long as possible before buying a new GPU or get a GTX 760 (X 2 SLI), 770, 780 or HD7970 (with the focus on graphics processing for the next gen consoles the sensible buyer is looking beyond 2GB GPU memory cards to future proof as much as possible).
Change cooler to a watercooled set up (which one depends on the case)
Let the GF choose the case to match the decor of the living room (this is definitely the quietest option)!!!!!