graphics card query
motherboard - intel 945gzisprocessor - intel c2d 2.2ghzram - 2gb (ddr2)which graphics card will it support (detail)
you can get a r7 250 ddr5. Don't go with the gt640 ddr3 both of them would cost you about the same, although r7 250 would be bottlenecked a bit but it could be useful if you would upgrade your build later.
I had a gt630 ddr5 1gb with a c2d 2.0ghz with almost the same specs and it performed ok, but when i swithced the cpu to a fx6300 the performance diff was notisable.
So, If you plan to upupgrade then get a 1gb ddr5 7750, otherwise I would recommend a gt630 ddr5(rest all will bottleneck more than their worth).
Another thing to check before buying a gpu is whether your psu is good enough, so posting some specs of your psu would be better for deciding.
[edit: on newegg I could find a gt640 ddr3 which cost lower than a gt630 ddr5 with mir, so you should consider that.]
r7 250: MSI R7 250 1GD5 OC $80
gt 640: MSI N640GT-MD1GD3 $50