You want dual x16 slots, you'll need a mobo with an NF200 chip. Sandy Bridge only gives you sixteen lanes, total. Good motherboards will split that two ways x8/x8 for dual videocards, crappy ones will give the second card four lanes from the southbridge. The motherboard you're looking at falls into the latter category. Actually, I'm not sure if it even supports dual videocards. Get a P67 or Z68 board, full ATX and proper lane splitting.
Noted, I'll look for that.
I would also recommend against a Caviar Green- go for a Black, preferably, or a different brand if your budget can't afford it.
Noted, I found a nice 7200rpm Black for only $15 more.
The Antec 300 is a nice case, definitely recommended. A Crossfire rig might be too much for it, though, it is a fairly small case by today's standards (though massive by yesterday's).
Yeah, I hadn't thought of that. This Cooler Master
looks nice, and free shipping.
Lastly, if you have no plans to overclock and don't intend to use the integrated video, a vanilla i5-2500 will do just fine.
The 2500k is $5-$10 more expensive than the other version. Plus, it allows me the ability to overclock in the future, if I decide to.