I'm having good luck with the Gigabyte GA-MA785GM-US2H and the same chip you want to use. It has onboard audio (Realtek ALC889A codec supporting up to 7.1 channel surround sound), onboard video (ATI Radeon HD4200) integrated in the NorthBridge (AMD785G) with HDMI, DVI-D and D-Sub outputs, 1 PCI-e x16 slot, 1 PCI-e x 1 slot, and 2 PCI slots, onboard networking, more USB2.0 ports than you could probably ever use, 4 DDR2 memory slots w/ dual channel support and memory overclocking up to 1200 MHz, and can be used for any AMD CPU up to and including the Phenom II.
If you have used MLB.TV premium, this setup will deliver a picture at the highest picture quality setting without freezing. If you haven't, this takes a LOT of graphics and CPU horsepower. I got mine in a bundle with the same processor for $135 from Tiger Direct, but I'm sure you can find it from quite a few sources. MB alone was $80.