I would go for the Neo ECO 520C.
This PSU has been made by Seasonic.
It provides a single +12V output that is rated for up to 44A (480W) (a little more power than the EarthWatts green) . But it's not over current protected.
It has, like the Earthwatts green, one 6-pin and one (6+2)-Pin PCIe conectors.
It presents a bit less efficiency (80 Plus Certification) than the Earthwatts green. (It's the only other positive point for the Earthwatts green over the Neo Eco)
Same warranty: 3 years.
I presents a better quality capacitor in the primary: one Japanese cap from Chemi-Con (330µf 400V) rated at 85°C . On the secondary all the caps are Taiwanese from Su'scon.
It presents a better noise and ripple supression.
It runs a bit quieter than the earthwatts green due to its medium speed 120mm from ADDA.
Anyway, at the same price, I would go for the Earthwatts 500W (EA-500D "gray" model). It has a worse efficiency (80 plus certification) but a better built quality:http://www.newegg.com/Product/Product.aspx?Item=N82E16817371007&cm_re=antec_500w-_-17-371-007-_-Product