yeah we forgot to tell you that it needs to be a brisbane. it will run much cooler and clock way higher (i have it and the evga mobo you listed), like v-dogg says.
my zalmann 9500 cools very well, it costs a little more than the arctic cooling. probably not worth the price increase, though.
as far as the audio card, as b1g says, you dont really need it. although, i bought an audigy zs2 (the cheap one, like 30 bucks), and it really makes a difference in my games i think. plus it comes with a cool little EQ that is great when you are burning cds.
good luck! your build looks great otherwise!