Sylki,

What is the connector? ATX? PCIe, PCIe 2.0? Do you know? How old is your PC if you don't know?

nVidia is the chipset, lots of different vendors make nVidia cards.
What are you looking to spend US$?
Do you do a lot of open GL (Hardware) rendering or 3Delight (Software)rendering?
do you use your computer for games?