I run AMD Phenom X4 and I like them alot. These are priced well and provide a lot of bang for the buck.
Coolmaster makes very nice cases. I have one on my kids computer. Sturdy design.
I did not see a power supply on your list. What do you have planned for power? I think it is wise to always go as powerful as you can concerning the supply.
Asus makes good mobo IMO. However I have a MSI SL2 that Is a very nice board.
4 gig of ram is plenty IMO. The 64 bit OS will utilize your 4 gig without issue.