Well, I'm gonna tell you how I did it, because my screens have the same connectors as yours.
One to HDMI, one to DVI, and one using an ACTIVE adapter (from XFX) miniDP-DVI to DVI's third screen input.
In your case, I suggest the same.. Which ACTIVE ADAPTER??. Maybe one of these:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814999030 (this one is DP to DVI)
http://www.newegg.com/Product/Product.aspx?Item=N82E16815309008 (this one is mDP to DVI)
http://www.amazon.com/HIS-HMDPSDVIEYE-Mini-DisplayPort-Adapter-Eyefinity-ready/dp/B004RFGK30/ref=sr_1_9?s=pc&ie=UTF8&qid=1353361108&sr=1-9&keywords=active+adapter
Actually, it's pretty simple, once you have the right adapter.. Just plug them in and configure.. 
Best regards... 
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8320 @ 4,5 / 990FXA UD5 / 7950 @ 1150-6200 / Switch 810 / H80 / 16 GB RAM / 23" 5760x1080 / SSD 64GB RAID0 / Tr2 750W