If your purchase is end of July, you might want to wait & see if the Bulldozer chip has finally come out & how it stacks up with the Sandybridge. The FX990 mobos for bulldozer are coming out in ~1 week.
Based on your list, if it's for gaming i-5 2500k is good & you save ~$100+ pending if you have a microcenter you can pick one up for $179.99
The Raven RV02b-EW = one sexy looking case & I kind of wished I went for that vs my Haf-X
Adding another 4gb of ram will be nice
Other than that, solid build, as I'm guessing you're going to flash the 6950s to 6970s on that msi card.
Is the MB overkill? I went with it because of the x16/x16 in CF, does x16/x16 provide a major benefit over x8/x8. Also will the MB have enough room to fit the 6950s? I use to work distribution/oem and would build out systems but I've never messed with GPUs that take up 2 slots.
Some would say yes for the extra ~3~5% performance you get with x16/x16, but for some every performance gain is a plus. That's ultimately up to you to decide if it's worth the extra ~$100 bucks.
I took at the motherboard layout on newegg & the 2x pci-e x16 slots are spaced like most other boards, so I don't really see any advantage there. You won't have any issues with spacing based on the motherboard & with a full tower, it shouldn't be a problem either.
I haven't had the chance to work with the sexy Raven RV02b-EW case, but if you're worried about spacing due to the vertical layout of the mobo, for basically the same price you can go with the Haf-X which is a traditional layout with TONS of room & one of the best airflow cases. It's the primary reason why I ultimately didn't go for the Raven RV02b-EW.
The only reason I was looking at the Z68 was because it was popping up on the "best gaming pcs" as of May. I've been out of system building (use to work disti and OEM) so I haven't built anything in 3 years and have no idea on the best values now. What would your opinion be a good Sandy Bridge board? I've never OC but plan on doing it with this system.
If you aren't using the Z68 features, you can get a better value from a P67 board. And since 8x/8x crossfire is identical to 16x/16x, I'd look at these two boards. The ASRock board is a crazy value for what it's worth (high overclocking and crossfire), the ASUS board is there if you feel more comfortable buying a bigger name board with additonal bells and whistles.
To update, so far I've purchased
OS: Win 7 Home Premium 64 Retail
MB: Asus P8P67
HDD: WD Caviar Black 1TB
PSU: Thermaltake TR2 RX 750W Bronze
Purchased these together locally off craigslist for $650 (Newegg: $850)