是否找有雙PCIE-16的主機板就可以了：YES

Windows 7 官方說明說需要每張顯卡都要接螢幕或是接 VGA dummy plug
http://folding.stanford.edu/English/WinGPUGuide#ntoc4
# If you run Windows Vista/Win7, you need to have each GPU connected to a monitor (a KVM can also work but not all models of KVM will provide a signal when it's not switched as current monitor) or a VGA dummy plug.

我實際測試Win7企業版X64沒接螢幕也正常

軟體設定部分可參考：
1) 官網： http://folding.stanford.edu/English/WinGPUGuide#ntoc4
2) http://forum.coolaler.com/showthread.php?t=191766