@BladeSinner pick a case first, then work from there.
Most wattage draw comes from voltage so I'd still go for a K CPU, overclock AND undervolt it.
A lot of HyperX memory is 1.65V, make sure to get 1.35V or 1.5V
GPU get a Gigabyte/ASUS custom one
Cooling and GPU depend on your case and how sensitive you are to pump noise.
Yup. For not that much more you can get a BP550 though:
http://www.newegg.ca/Product/Product.aspx?Item=N82E16817371016
and the 270x / 760 are a nice bump up from a 660 for $50.
See the NEWS section in the bottom of the OP.