If you can get an r9 290x or gtx 980 then do so. It will be less of a hassle then using a dual gpu set up. Gtx 980 is faster then a 290x but both are good and if you don't have a preference(AMD or NVIDIA) then get the cheaper card. Yes the 290x will use more power and does run hot but any after market cooler by MSI, Sapphire, or XFX will be be fine.