Green Radience gave you some good advice. There are some things to consider, however.
I would definitely buy from the "Egg". If you take some time to watch their site, you can get some good rebates. For instance, the DFI Ultra-D is now $122.99. It probably was $108 when he made the link.
You can get 2GB (2 X 1024) DDR (500) PC-4000 OCZ EL Gold Gamer for @162.99 after $40 rebate:
You can also save some money on HDD's. See my sig.
Here is the link to the DFI tech website:
Go there for some good advice, also. They have much to offer someone who uses their mobos and wants to build their own box.
Read as much as you can before making a decision. There are many places to save money and get a good system.