There's nothing wrong with the displays. If I were you, I'd simply invest in a graphics card with a pair of DisplayPort connectors and get the correct cables, as any Thunderbolt port will accept a mini DisplayPort input. That makes a lot more sense to me than waiting for one of these boards that may or may not work. Something like a Radeon HD 6870 will do the job, and if you're in the US, they can be had for $160 or less with rebate these days.
Something like this would do the trick
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161396
That said, you might want to aim for a slightly more expensive 2GB card due to the high resolution of those displays if you do anything 3D related, as they'll chew away on texture memory, so this $190 (after MIR) card might be a better option
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150563