Dell Inspiron 531s

Im not good with computer spec finding this what i know
Processor, Sempron, LE-1300, 2.3 512K, 1C, G2
Hard Drive, 160GB, S2, 7.2K, 8M Unleaded, WD-SEQ
4GB RAM
Graphic Processor NVIDIA GeForce 6150 SE
and
Resolution: 1024 x 768
Depth: 32-bit Color
Core Image: Software
Main Display: Yes
Mirror: Off
Online: Yes
Quartz Extreme: Not Supported

I used to have Leopard 10.5.8 or something like that but quartz extreme didnt work. Could someone link me to a graphic card that will work?