R9 290 requires 31 Amps on the 12v rail & a 550W PSU minimum
Cooler Master V700 has 58 amps/696W on the 12v rail ( 4x 6+2-pin PCIE connectors) plenty of power & cables.
The V series is Seasonic OEM & top quality, Tier one on the PSU unit tier list -
The highest quality and most stable PSUs available on the hardware market today. Highly recommended for any situation
http://www.tomshardware.co.uk/answers/id-1804779/power-supply-unit-tier-list.html
(VS series is perfectly fine as well, but not quite as a good as the V series)
Only trouble with the V & VS series is that they can be a little pricey depending on where you live, so consider other options as well. EVGA's G2 series is solid & a Tier One PSU, it's usually priced really well, if available.
Supernova G2 750W:
http://pcpartpicker.com/part/evga-power-supply-220g20750xr
Supernoga G2 850W: http://pcpartpicker.com/part/evga-power-supply-220g20850xr