Yes, it is.
This MB supports PCI-ex 2.0. There's a little different in raw potential between pci-ex 2.0 and 3.0 but isn't noticiable. if i remember well is about 2%-4% slower.
If you want to buy that card, buy it. It will works.
850w psu is a little bit high for this video card.
If you want to run one single 760 go with a brand 550w (xfx, corsair, seasonic, ecc)
yes the motherboard will handle the 760 no prob but you might run into issues with the length of the card that you choose. You have to watch out for those SATA plugs. A long graphics card might cover them or at least the top two.