All of these boards offer the possibility to set up sli.
I recently dealt with this same issue, and after going through many comparisons, reviews, and tests of the boards, I finally chose the Asus P8Z68-v Pro/Gen3. I upgrade graphic cards and CPU's quite often. So, I wanted a quality board that would support the next generation of graphic cards and CPU's. This one does that, and it is a quality product. It is PCIe 3.0 ready and comes with all of the latest v series drivers. So, if you plan on buying it soon, you won't have to download updates. This board offers a nice software package too. You can pick and choose which features and/or Utilities you want to enhance. For example, you may want to use GPU boost, EZ flash 2, Crash free bios 3, or the AI tweaker. So far, I haven't experienced any software or hardware problems and the Bios is easy to use. There are many advanced options for experienced users, and for beginners, the EZ mode, which basically does everything for you. The manual is also full of helpful information, to assist you with everything from board layout to installing your main components and connections, from explaining features and software to troubleshooting, setting up sli configs, and so on. If I had to choose again, I would still choose this board.
Here are my specs.
Intel i7 2600K
16GB Corsair Vengeance Blue 1600Mhz RAM @1.5v
HAF X RC-942 black full sized tower
Corsair H80 Liquid Cooler
1x 240Gb OCZ Vertex 3 Sata 600
1x 1TB WD Caviar Black WDFAEX1002
LG SuperMulti Blue BH10LS30
Scythe Kaze Master Pro fan control KM03-BK
2xMSI n580GTX Lightnings sli
Windows 7 Ultimate 64bit