For that price you should be able to include the i5-2500k (which is needed if you want to overclock) and 8 gb of RAM. The speed and amount of RAM does not affect your processor or how much you can overclock it.
If you don't ever plan to SLi a 500W system is more than sufficient for most setups.http://www.newegg.com/Product/Product.aspx?Item=N82E16817371016
Much better PSU. The Corsair CX series are horrible and Corsair is overpriced in general.