First when you use 3 or more sticks of DDR, it has to be *registered* (kinda like buffered, but not quite). Crucial sells 3 kinds of DDR: Plain, Registered, and Registered +ECC. The registred costs $5 per stick and runs *slightly* slowly than the plain. The Registered +ECC costs $10 more per stick and also is *slightly* slower than the plain.
Also, I just bought an EPOX 8K7A from newegg (great price!) and everything is working great with it. To disable the sound in BIOS just hit DEL and setup, choose Integrated Peripherals, and set AC97 to Disable.
One word of warning about the EPOX. Do *NOT* use a Netgear FA311 or FA312 network card with it, the NIC is incompatible with many (including Epox) AMD 761 chipsets. If you use a Netgear card, the computer will not power on and boot properly, or restart from windows.
My $0.02