If I were you I would get a Phenom II instead. They perform better and overclock better as well.
AFAIK when you run 4 sticks of RAM with a Phenom it won't run at 1066, so you may as well get some 800 instead. I would also buy RAM rated at 1.8V (G-Skill & Mushkin are good).
I don't think you'll notice the difference in 1GB versus 512MB on a 4670.
As far as the PSU, a good quality 300W+ would be plenty. I'd suggest Antec Earthwatts 380 or 430, Seasonic S12II 380 or 430, or Corsair VX450.