What wattage power supply would I need for the system below

[Pulse_V_Nitroz]

I plant to build the system below, how ever I do not know what PSU I need.
http://uk.pcpartpicker.com/p/Dnx4hM

Please note:

I plant to add another set of
G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory

I also plan to add another
MSI Radeon R9 290X 4GB TWIN FROZR Video Card

And possibly another
Samsung 840 EVO 120GB 2.5" Solid State Drive


I know there is a PSU on this list, it is just a place holder.

 

[Bossyfins]

http://uk.pcpartpicker.com/part/evga-power-supply-220g20750xr

This is a good PSU for your needs

 

[clutchc]

I would go bigger and better for dual 300W cards and a 125W processor. Especially if you intend on OC'ing. An 850W at least... for some headroom. http://uk.pcpartpicker.com/part/xfx-power-supply-p1850bbefx

 

[Pulse_V_Nitroz]

Okay I think Im getting the 750 watt, seems a lot, and i'm not 100% sure if im getting the second GPU but I will still get the 750 watt psu encase

 

[gskill support]

650W+ GOLD and you'll be just fine.

So 750W or more will be a good amount of headroom

 

[clutchc]

Trust me, my single 290X (OC'ed) consumes every bit of 300W (and more) according to my kill-o-watt meter. Dual 290X cards maxed out plus a stock 125W processor maxed out (725W) is already crowding an 87% Gold 750W even w/o the rest of the system included. Don't cause yourself problems by going too small.