Looks good to me, but may i recommend the [SLI] eVGA Nvidia nForce 780i SLI Chipset w/7.1 Sound, Gb LAN, S-ATA Raid, USB 2.0, 3-Way PCI-E MB 3-Way SLI Motherboard. Personally I like it more, and has a 3way SLI (even though 3 GTX 280s is kinda impractical).
Wait for more responses cause im only 15 so i may be missing some details