EXTREME GAMING SYSTEMS

Your proposed rig is extreme for sure.. Extremely pointless..

Not really enough info as to what you want, the six core and 2 ati 6870s sure. As for the 198g of dual channel, not on anything other than a server board that I can think of but even then its gonna be extremely expensive and not at all useful other than bragging rights. As for the 10k rpm raptor, sure, but if its speed you're going for I'd go with a SSD. Hope this answers your question.

Did you just win the lotto?  

198 gig of dual chanel ram, wow.........never heard of anything more pointless.
to be honest 24 gig is the most anybody should ever consider doing.

12 gig of cl6 tripple chanel would be substantially more than suffice

Why not go for Quad Ares Cards?
LOL.....
And change to 2 or 4 Magny Cours...... 8 to 12 core AMD's....
Then the 198 Gigs will make a lot of sense....
But then coming to think of it, do you get a electricity bill?
That's going to cost you more than the rig every month if have it always running....  
So what's the deal? No, seriously? what made you come to this sort of a extreme setup?
What makes 198Gigs better than 8 Gigs...?
What makes a 6Core AMD the choice instead of i7Extreme.... when it comes to the "Extreme" setup you put in front of us...
Why the Raptor and not the Revo?
I'd love to have those answers.....