Here are my reccomendations in order of best to least best (all are great boards, but this is my opinion as if i were going to buy it) I have tested all of these boards myself hands on, i have benchmarks for all of em if u need it.

1. http://www.newegg.com/Product/Produc...82E16813188090
2. http://www.newegg.com/Product/Produc...2E16813131666R
3. http://www.newegg.com/Product/Produc...2E16813128472R
4. http://www.newegg.com/Product/Produc...82E16813131658 (microatx but has 2x 16x pcie)

And the p6t se i have does support SLI you have to disable the 4x pcie slot in the bios (to force 16x/16x on the other 2) you may need to update your BIOS and get some "real" SLI bridges (the flexible ones are the best) if your using ISBoxer SLI isn't going to help you unless you only run 1 monitor. (unless something has changed since i done my testing/benching in december with multi gpu + multi monitor)

Feel free to PM me if you have any questions or need any of my benchmark results.