How much vram do i need for my graphics card??

I'd get the 4 gb VRAM one because you can raise the clock yourself, however, you cannot raise memory  .

good point    

if you have all this cash, why not buy something like a yamasaki catleap 1440p monitor. then you can take advantage of the 680. otherwise a 670 would still be overkill for 1080p

id just get a good gtx670 like the msi power edition. i have no idea why you want to blow your hard earned cash (unless you won the lottery or something)

the most elitest 680 right now is the msi lightning gtx680. its better than the 4gb classified because you can actually overvolt using software (the classified needs this EVbot which costs a extra 200 dollars). msi will probably do a xtreme edition where it has 4gb of vram.

if it is a single monitor, id just get the 2gb. you cant use the 4gb buffer if your not running multiple monitors