I recommend getting an ASUS P6TD, its a newer version and i never had a problem with asus...or gigabyte, both are excellent. I don't see why you would get a 850watt for that. A 600-700watt good quality PSU would do fine. I guess you plan on Crossfiring or SLI'ing. If you are spending a lot on your system, get Mushkin Enhanced Redlines 6GB Tri-Channel. They have 1600mhz and the best Latency for thier frequency at CL6. Also, are you planning on Overclocking?