No, Don't get the 9500, they are horrible, and that 1gig is a gimmick, they can't really handle over 512, try to get a HD4670/9600GT or above, don't get the 9600GSO though.
Basically:
9800GTX+/GTS250=HD4850
8800GTX/8800GTS512mb=HD4770
9800GT/8800GT=HD4830
9600GT=HD4670
9600GSO=HD4650
9500GT=HD3670