?? I think you stand a better chance with a AMD card then you do with a NVidia card over a 700 series ? you just need to research that and see if anyone has any issues with that board and any latest cards ?
may just be as simple as flashing the board to it latest bios that may support the latest cards ?? some time on some boards they don't even get that and stuck using older cards
thing is I would of thought a AMD 200 series would be safe
see like here with NVidia 900 series
http://forums.evga.com/New-GTX-970-FTW-Works-in-4x-Slot-but-not-16x-Slot-m2246378.aspx
''Just tried a New PSU a friend bought today for him. Wasnt the issue. Already flashed my BIOS and reset the CMOS. I guess ill buy a New mobo. I hope a z77 will work.''
https://www.reddit.com/r/techsupport/comments/2rwbsm/msi_gtx_970_gaming_not_recognized/
https://forums.geforce.com/default/topic/809811/from-gtx-660-to-gtx-960-now-pc-wont-boot-/?offset=14
you kinda see it for the most part NVidia 900 or above cards that struggle on older boards like yours you don't see maybe one or two with a AMD card reported ??
then if this is your board you see the bios dates are 2012 ?? that's well behind the newer cards release dates and not current to them ??
https://www.asus.com/Motherboards/P8Z68VGEN3/HelpDesk_Download/
all you can do is buy , try , and hope it don't make you cry