I might not be seeing it clearly, but in the link for you computer, is the motherboard backwards? Looks like it is. If thats true, you won't be able to reuse that case.
Your budget isn't really falling in line with the parts your choosing. You chose 150$ worth of parts there, all of them bottom end. I wouldnt consider that setup anywhere near midrange for gaming.
Replace that hard drive with one like this, if your looking to keep the noise and power consumption down, also specs are much better:http://www.newegg.com/Product/Product.aspx?Item=N82E16822136490&cm_re=wd_green-_-22-136-490-_-Product
Also, that power supply is undersized and not somthing you should skimp on. Spend more than 15$ Especially if your planning to do any kind of overlocking.