Well, 9800 GX2 needs 575W.
Where are u shopping?
most likely newegg, since rosewill is a newegg home brand(albeit you can buy it off the rosewill store in amazon as well)
To OP, the reviews for the 2
rosewill green 630whttp://www.hardwaresecrets.com/article/881
antec neo eco 520chttp://forums.guru3d.com/showthread.php?t=317192