The 6670 is the next best card. I am not too sure if you computer has a PCI-E x16 1.0 slot or PCI-E x16 2.0 slot. Because 2.1 cards (such as the 6670) sometimes don't work on 1.0 slots.
In either case, if you have problems with the card you can also look at the gt 440.
Actually, my computer is a debranded version of the P6616F. I would've mentioned this but I knew the PCI slot wouldn't be a concern. This one comes with a 2GB stick of RAM and a different motherboard. The motherboard is a Foxconn 2AB1. ( http://www.findlaptopdriver.com/foxconn-motherboard-2ab1-specs-12242010h37
) It comes with a PCI-E x16 2.0 slot and 3 PCI-E x1 slots. Again, apologies for the confusion.