You may not want that motherboard. Though it has 2 GPU slots note that one of them is referenced as running at 4x speed. You wouldn't want to run dual card with that I don't think. The Asus P7P55D PRO
at $170 is probably what you want if you are ever going to consider dual card. If you are going for the kind of board that is really only good for one GPU you could go with a Gigabyte
for teh cheap at $110 (-$40). (Though the Asus one you originally linked does have that fancy 12 phase power.)
Also, I'd say go with the OCZ Gold 4 gig DDR3-1600 kit
it's $5 cheaper than Corsair, and it's got slightly tighter timing. The G.Skill Ripsaws
used to be king with super tight timing at priced at $95, but they seem to have spiked up quite a bit. If you don't mind slightly slower timing than the Corsair, you can save a bunch with the OCZ Obsidian 4 gig DDR3-1600 kit
currently at $60 post rebate.
I'd say the XFX 5770
at +15 over Sapphire is probably worth it for the double lifetime coverage (vs. two year). Your choice though.
The EarthWats is likely fine, but you may want to check for reviews to be sure it doesn't run max fan speed. (It shouldn't since it's designed to save energy, but I vaguely recall reading a review once which said it did (run at max).)
I'm fairly certain the green drives are not good for gaming due to having slower spin speeds. I read an article back in the day and recall that they pointed to several factors which made them a poor choice for gaming or heavy media use. (Light media was 'ok'.) I don't see anywhere that references it's RPM speeds at NewEgg or WD. Though a fair bit more, I'd say stick with the WD Black 1 Tera
at $110 if you are going to be gaming.