Your PC will run very quietly with the ninja, built one almost exactly the same just the older GTS and 520w corsair which I would also recommend as you don't need 620W.
I know Blitzen you mentioned that it would be better to "shop around" for a PSU but i want YoYo to build the system so I need to come to a satisfactory choice over PSU. Is 620W overkill for that spec? Please recommend one thats good, and pref not gonna drain my electricity away for no reason.
Thanks