Only sever boards support dual processors. LGA1156 is a home socket, not a server socket, furthermore, the i5 655k (nor any i3/i5/i7) will don't support being using in a dual processor configuration.
If you want to run a dual processor board you'll have to either look to something in the server market, or like the EVGA SR2
http://www.evga.com/articles/00537/ at the extreme high end.
Either way, you'll be looking at a Xeon processor based off the LGA1366 socket. (The same socket the high end i7's use, but only the Xeon version of the chips will work in dual processor mode)
Short answer, none exist that meet your requirements because they are incompatable.