Looking for your opinions and input

[Dzzope]

A note on the brand preference of ati.. and that your playing wow..

I had a 5770 and a 5850 in my old and current rig..

Random graphics glitches, big black squares everye where.. Wow doesn't really like ati it seems (did alot of checking at the time)
It may have gotten better since. But you'll have to research the issues yourself.

I switched to a 560 ti and I haven't ever had even a slight hiccup.
I know you said it's non-negotiable.. But serriously check it out first.

As for GPU handling sound... I would suggest you stick to the on-board and buy a xonar or something if it's not sufficient.
The sound from graphics card is bound to impact performance in some way and is gotten through HDMI. so you may have connectivity problems.