Get a 120/128gb SSD. They have plenty of space for all programs and games. Buy Samsung 830 or 840, or Vertex 4. You have to buy the ssd first, cuz you will want to load Windows and all programs on it. (I bought a 500gb HDD first and then had to switch to my new ssd after. annoying.) Get a 1TB HDD, prices are great.
Get a 600W PSU or 550W. Just make sure it is at least Bronze 80 certified. Stick to 520-600W, cuz you don't need anymore than that.
I have the MSI 660 ti, but I don't recommend it. Buy a 7950. The new drivers make it awesome. It will beat the 660ti at almost everything.