Dude if its a temp PC this comp has nothing in worth upgrading. Save the money you are going to spend on the Video Card and just save it toward the next comp you are building. A new vid card isnt going to help you that much.
If i were you i wouldnt invest another penny in this comp jsut save for a brand new one. Upgrading can only be taken back so far. P3 boards are taking it almost too far.