I encountered the same problem as you (HD 3200=LONG way from being supported if ever). If you're willing to stick to ATI, the Sapphire HD 3650 is about $50 and after a little bit of fiddling to find the right driver, it works like a charm.
The audio can easily be fixed with Taruga's patcher and dump file for the ALC889a.

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Custom Hackintosh...AMD Athlon X2 5000+ (2.6 GHz) on GA-MA78GM-S2H...Linksys WMP300n Wireless...ALC889a sound...ATI HD 3650 PCIe...1 GB DDR2 RAM...320GB Western Digital SATA + 200GB Seagate IDE HDD...Rosewill DVD-RW IDE...Running Kalyway upgraded to 10.5.7...All Fully Functional