Ultimate Gamer :
No Crossfire with that board.
Darn it.One more question Would you buy this 290
Link http://www.ebay.com/itm/PowerColor-AMD-Radeon-R9-290-4GB-GDDR5-OC-2DVI-HDMI-DisplayPort-pci-e-Video-/121319792062?pt=PCC_Video_TV_Cards&hash=item1c3f391dbe
No, the reference cards run really hot and throttle a ton, you would be better off getting a new gtx 770 for that price.
GTX 770's can be SLI'd on a 750w PSU, I don't think Coolermaster make high quality PSUs but i may be wrong and that could be a good one, someone else will have to do the research - I don't have time right now.