I hear this motherboard is very compatible but will sound work or will I need a sound card?

The Cmedia 9761A built into your motherboard doesn't have a dump file listed in the AppleHDA patcher thread. That doesn't mean that it won't work. You'll just have to get your own linux dump file of it and try it out that way.

I have this motherboard and the sound works without any necessary patching on 10.4.8. One caveat- if you have a mac keyboard the volume controls on the keyboard do not work.

The video, ethernet and SATA work fine too. It's a great motherboard for a hackintosch. You will want to get a different video card though the built in one will give you video in OSX but it won't give you quartz or core.

So what's a good cheap card for it?

I put a Nvidia 6200le in mine and patched with the Neo natit installer. I used a Pentium D 805 for the processor and it scores just a couple of points lower than the first generation MacBook Pro in Xbench. It's fast enough for most applications.

The motherboard runs OS X rock solid. It doesn't go fully to sleep; it tries but the fans don't turn off it goes into a sort of a semi power limbo. It does come out of this state without crashing. Also as previously mentioned, the volume controls don't work. Other than those minor issues, it has been hassle free.