Your hard drive seem to be rated good but i am not positive that is the best brand. Also, you need a power supply to, i am not sure if your case came with one but if u get a high graphics card, then you need a good power supply. If you get a low power supply, it will cause your computer a lot of energy needed for that graphics card, processor etc. I am not familiar with good brands for PSUs (power supply units), but i found this one, 650 watts.
As for the motherboard, that motherboard was just an example of a motherboard that you would need (not sure if it was 100% right for your specs) but just make sure your mothreboard is compatible with amd 64x2 antlon.
If you want 1 gig---http://www.newegg.com/Product/Product.asp?Item=N82E16820145440
Also, if this is a gaming computer, you will NEED a sound card..Creative is probably the best brand for sound cards, get a sound blaser audigy...
Here is one,
Here is a motherboard that seems good http://www.newegg.com/Product/Produc...82E16813127222
If you will install anything extra such as tv tuners or anything, get a motherboard with a lot of PCI express x16 slots so you will have room. Check with someone who is more expirienced then me to make sure all these parts willl fit because there are certain specs that have to be accurate that I am not sure of, so make sure that you know these will work.
Plus, if you wana see kick ass cases...go to
<---they have realllly cool cases and stuff there.